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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>psql</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="app-pgrestore.html" title="pg_restore" /><link rel="next" href="app-reindexdb.html" title="reindexdb" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center"><span xmlns="http://www.w3.org/1999/xhtml" class="application">psql</span></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="app-pgrestore.html" title="pg_restore">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="reference-client.html" title="PostgreSQL Client Applications">Up</a></td><th width="60%" align="center">PostgreSQL Client Applications</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 12.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="app-reindexdb.html" title="reindexdb">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="APP-PSQL"><div class="titlepage"></div><a id="id-1.9.4.18.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle"><span class="application">psql</span></span></h2><p><span class="application">psql</span> — 
      <span class="productname">PostgreSQL</span> interactive terminal
    </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.4.18.4.1"><code class="command">psql</code> [<em class="replaceable"><code>option</code></em>...] [<em class="replaceable"><code>dbname</code></em>
    [<em class="replaceable"><code>username</code></em>]]</p></div></div><div class="refsect1" id="id-1.9.4.18.5"><h2>Description</h2><p>
     <span class="application">psql</span> is a terminal-based front-end to
     <span class="productname">PostgreSQL</span>. It enables you to type in
     queries interactively, issue them to
     <span class="productname">PostgreSQL</span>, and see the query results.
     Alternatively, input can be from a file or from command line
     arguments. In addition, <span class="application">psql</span> provides a
     number of meta-commands and various shell-like features to
     facilitate writing scripts and automating a wide variety of tasks.
    </p></div><div class="refsect1" id="R1-APP-PSQL-3"><h2>Options</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-a</code><br /></span><span class="term"><code class="option">--echo-all</code></span></dt><dd><p>
      Print all nonempty input lines to standard output as they are read.
      (This does not apply to lines read interactively.) This is
      equivalent to setting the variable <code class="varname">ECHO</code> to
      <code class="literal">all</code>.
      </p></dd><dt><span class="term"><code class="option">-A</code><br /></span><span class="term"><code class="option">--no-align</code></span></dt><dd><p>
      Switches to unaligned output mode. (The default output mode is
      <code class="literal">aligned</code>.)  This is equivalent to
      <code class="command">\pset format unaligned</code>.
      </p></dd><dt><span class="term"><code class="option">-b</code><br /></span><span class="term"><code class="option">--echo-errors</code></span></dt><dd><p>
      Print failed SQL commands to standard error output. This is
      equivalent to setting the variable <code class="varname">ECHO</code> to
      <code class="literal">errors</code>.
      </p></dd><dt><span class="term"><code class="option">-c <em class="replaceable"><code>command</code></em></code><br /></span><span class="term"><code class="option">--command=<em class="replaceable"><code>command</code></em></code></span></dt><dd><p>
       Specifies that <span class="application">psql</span> is to execute the given
       command string, <em class="replaceable"><code>command</code></em>.
       This option can be repeated and combined in any order with
       the <code class="option">-f</code> option.  When either <code class="option">-c</code>
       or <code class="option">-f</code> is specified, <span class="application">psql</span>
       does not read commands from standard input; instead it terminates
       after processing all the <code class="option">-c</code> and <code class="option">-f</code>
       options in sequence.
      </p><p>
       <em class="replaceable"><code>command</code></em> must be either
       a command string that is completely parsable by the server (i.e.,
       it contains no <span class="application">psql</span>-specific features),
       or a single backslash command. Thus you cannot mix
       <acronym class="acronym">SQL</acronym> and <span class="application">psql</span>
       meta-commands within a <code class="option">-c</code> option. To achieve that,
       you could use repeated <code class="option">-c</code> options or pipe the string
       into <span class="application">psql</span>, for example:
</p><pre class="programlisting">
psql -c '\x' -c 'SELECT * FROM foo;'
</pre><p>
       or
</p><pre class="programlisting">
echo '\x \\ SELECT * FROM foo;' | psql
</pre><p>
       (<code class="literal">\\</code> is the separator meta-command.)
      </p><p>
       Each <acronym class="acronym">SQL</acronym> command string passed
       to <code class="option">-c</code> is sent to the server as a single request.
       Because of this, the server executes it as a single transaction even
       if the string contains multiple <acronym class="acronym">SQL</acronym> commands,
       unless there are explicit <code class="command">BEGIN</code>/<code class="command">COMMIT</code>
       commands included in the string to divide it into multiple
       transactions.  (See <a class="xref" href="protocol-flow.html#PROTOCOL-FLOW-MULTI-STATEMENT" title="52.2.2.1. Multiple Statements in a Simple Query">Section 52.2.2.1</a>
       for more details about how the server handles multi-query strings.)
       Also, <span class="application">psql</span> only prints the
       result of the last <acronym class="acronym">SQL</acronym> command in the string.
       This is different from the behavior when the same string is read from
       a file or fed to <span class="application">psql</span>'s standard input,
       because then <span class="application">psql</span> sends
       each <acronym class="acronym">SQL</acronym> command separately.
      </p><p>
       Because of this behavior, putting more than one SQL command in a
       single <code class="option">-c</code> string often has unexpected results.
       It's better to use repeated <code class="option">-c</code> commands or feed
       multiple commands to <span class="application">psql</span>'s standard input,
       either using <span class="application">echo</span> as illustrated above, or
       via a shell here-document, for example:
</p><pre class="programlisting">
psql &lt;&lt;EOF
\x
SELECT * FROM foo;
EOF
</pre><p>
      </p></dd><dt><span class="term"><code class="option">--csv</code></span></dt><dd><p>
      Switches to <acronym class="acronym">CSV</acronym> (Comma-Separated Values) output
      mode.  This is equivalent to <code class="command">\pset format csv</code>.
      </p></dd><dt><span class="term"><code class="option">-d <em class="replaceable"><code>dbname</code></em></code><br /></span><span class="term"><code class="option">--dbname=<em class="replaceable"><code>dbname</code></em></code></span></dt><dd><p>
       Specifies the name of the database to connect to. This is
       equivalent to specifying <em class="replaceable"><code>dbname</code></em> as the first non-option
       argument on the command line.
      </p><p>
       If this parameter contains an <code class="symbol">=</code> sign or starts
       with a valid <acronym class="acronym">URI</acronym> prefix
       (<code class="literal">postgresql://</code>
       or <code class="literal">postgres://</code>), it is treated as a
       <em class="parameter"><code>conninfo</code></em> string. See <a class="xref" href="libpq-connect.html#LIBPQ-CONNSTRING" title="33.1.1. Connection Strings">Section 33.1.1</a> for more information.
      </p></dd><dt><span class="term"><code class="option">-e</code><br /></span><span class="term"><code class="option">--echo-queries</code></span></dt><dd><p>
      Copy all SQL commands sent to the server to standard output as well.
      This is equivalent
      to setting the variable <code class="varname">ECHO</code> to
      <code class="literal">queries</code>.
      </p></dd><dt><span class="term"><code class="option">-E</code><br /></span><span class="term"><code class="option">--echo-hidden</code></span></dt><dd><p>
      Echo the actual queries generated by <code class="command">\d</code> and other backslash
      commands. You can use this to study <span class="application">psql</span>'s
      internal operations. This is equivalent to
      setting the variable <code class="varname">ECHO_HIDDEN</code> to <code class="literal">on</code>.
      </p></dd><dt><span class="term"><code class="option">-f <em class="replaceable"><code>filename</code></em></code><br /></span><span class="term"><code class="option">--file=<em class="replaceable"><code>filename</code></em></code></span></dt><dd><p>
       Read commands from the
       file <em class="replaceable"><code>filename</code></em>,
       rather than standard input.
       This option can be repeated and combined in any order with
       the <code class="option">-c</code> option.  When either <code class="option">-c</code>
       or <code class="option">-f</code> is specified, <span class="application">psql</span>
       does not read commands from standard input; instead it terminates
       after processing all the <code class="option">-c</code> and <code class="option">-f</code>
       options in sequence.
       Except for that, this option is largely equivalent to the
       meta-command <code class="command">\i</code>.
      </p><p>
       If <em class="replaceable"><code>filename</code></em> is <code class="literal">-</code>
       (hyphen), then standard input is read until an EOF indication
       or <code class="command">\q</code> meta-command.  This can be used to intersperse
       interactive input with input from files.  Note however that Readline
       is not used in this case (much as if <code class="option">-n</code> had been
       specified).
      </p><p>
      Using this option is subtly different from writing <code class="literal">psql
      &lt; <em class="replaceable"><code>filename</code></em></code>. In general,
      both will do what you expect, but using <code class="literal">-f</code>
      enables some nice features such as error messages with line
      numbers. There is also a slight chance that using this option will
      reduce the start-up overhead. On the other hand, the variant using
      the shell's input redirection is (in theory) guaranteed to yield
      exactly the same output you would have received had you entered
      everything by hand.
      </p></dd><dt><span class="term"><code class="option">-F <em class="replaceable"><code>separator</code></em></code><br /></span><span class="term"><code class="option">--field-separator=<em class="replaceable"><code>separator</code></em></code></span></dt><dd><p>
      Use <em class="replaceable"><code>separator</code></em> as the
      field separator for unaligned output. This is equivalent to
      <code class="command">\pset fieldsep</code> or <code class="command">\f</code>.
      </p></dd><dt><span class="term"><code class="option">-h <em class="replaceable"><code>hostname</code></em></code><br /></span><span class="term"><code class="option">--host=<em class="replaceable"><code>hostname</code></em></code></span></dt><dd><p>
      Specifies the host name of the machine on which the
      server is running. If the value begins
      with a slash, it is used as the directory for the Unix-domain
      socket.
      </p></dd><dt><span class="term"><code class="option">-H</code><br /></span><span class="term"><code class="option">--html</code></span></dt><dd><p>
      Switches to <acronym class="acronym">HTML</acronym> output mode.  This is
      equivalent to <code class="command">\pset format html</code> or the
      <code class="command">\H</code> command.
      </p></dd><dt><span class="term"><code class="option">-l</code><br /></span><span class="term"><code class="option">--list</code></span></dt><dd><p>
      List all available databases, then exit. Other non-connection
      options are ignored. This is similar to the meta-command
      <code class="command">\list</code>.
      </p><p>
      When this option is used, <span class="application">psql</span> will connect
      to the database <code class="literal">postgres</code>, unless a different database
      is named on the command line (option <code class="option">-d</code> or non-option
      argument, possibly via a service entry, but not via an environment
      variable).
      </p></dd><dt><span class="term"><code class="option">-L <em class="replaceable"><code>filename</code></em></code><br /></span><span class="term"><code class="option">--log-file=<em class="replaceable"><code>filename</code></em></code></span></dt><dd><p>
       Write all query output into file <em class="replaceable"><code>filename</code></em>, in addition to the
       normal output destination.
      </p></dd><dt><span class="term"><code class="option">-n</code><br /></span><span class="term"><code class="option">--no-readline</code></span></dt><dd><p>
       Do not use <span class="application">Readline</span> for line editing and do
       not use the command history.
       This can be useful to turn off tab expansion when cutting and pasting.
      </p></dd><dt><span class="term"><code class="option">-o <em class="replaceable"><code>filename</code></em></code><br /></span><span class="term"><code class="option">--output=<em class="replaceable"><code>filename</code></em></code></span></dt><dd><p>
      Put all query output into file <em class="replaceable"><code>filename</code></em>. This is equivalent to
      the command <code class="command">\o</code>.
      </p></dd><dt><span class="term"><code class="option">-p <em class="replaceable"><code>port</code></em></code><br /></span><span class="term"><code class="option">--port=<em class="replaceable"><code>port</code></em></code></span></dt><dd><p>
      Specifies the TCP port or the local Unix-domain
      socket file extension on which the server is listening for
      connections. Defaults to the value of the <code class="envar">PGPORT</code>
      environment variable or, if not set, to the port specified at
      compile time, usually 5432.
      </p></dd><dt><span class="term"><code class="option">-P <em class="replaceable"><code>assignment</code></em></code><br /></span><span class="term"><code class="option">--pset=<em class="replaceable"><code>assignment</code></em></code></span></dt><dd><p>
      Specifies printing options, in the style of
      <code class="command">\pset</code>. Note that here you
      have to separate name and value with an equal sign instead of a
      space. For example, to set the output format to <span class="application">LaTeX</span>, you could write
      <code class="literal">-P format=latex</code>.
      </p></dd><dt><span class="term"><code class="option">-q</code><br /></span><span class="term"><code class="option">--quiet</code></span></dt><dd><p>
      Specifies that <span class="application">psql</span> should do its work
      quietly. By default, it prints welcome messages and various
      informational output. If this option is used, none of this
      happens. This is useful with the <code class="option">-c</code> option.
      This is equivalent to setting the variable <code class="varname">QUIET</code>
      to <code class="literal">on</code>.
      </p></dd><dt><span class="term"><code class="option">-R <em class="replaceable"><code>separator</code></em></code><br /></span><span class="term"><code class="option">--record-separator=<em class="replaceable"><code>separator</code></em></code></span></dt><dd><p>
      Use <em class="replaceable"><code>separator</code></em> as the
      record separator for unaligned output. This is equivalent to
      <code class="command">\pset recordsep</code>.
      </p></dd><dt><span class="term"><code class="option">-s</code><br /></span><span class="term"><code class="option">--single-step</code></span></dt><dd><p>
      Run in single-step mode. That means the user is prompted before
      each command is sent to the server, with the option to cancel
      execution as well. Use this to debug scripts.
      </p></dd><dt><span class="term"><code class="option">-S</code><br /></span><span class="term"><code class="option">--single-line</code></span></dt><dd><p>
      Runs in single-line mode where a newline terminates an SQL command, as a
      semicolon does.
      </p><div class="note"><h3 class="title">Note</h3><p>
      This mode is provided for those who insist on it, but you are not
      necessarily encouraged to use it. In particular, if you mix
      <acronym class="acronym">SQL</acronym> and meta-commands on a line the order of
      execution might not always be clear to the inexperienced user.
      </p></div></dd><dt><span class="term"><code class="option">-t</code><br /></span><span class="term"><code class="option">--tuples-only</code></span></dt><dd><p>
      Turn off printing of column names and result row count footers,
      etc. This is equivalent to <code class="command">\t</code> or
      <code class="command">\pset tuples_only</code>.
      </p></dd><dt><span class="term"><code class="option">-T <em class="replaceable"><code>table_options</code></em></code><br /></span><span class="term"><code class="option">--table-attr=<em class="replaceable"><code>table_options</code></em></code></span></dt><dd><p>
      Specifies options to be placed within the
      <acronym class="acronym">HTML</acronym> <code class="sgmltag-element">table</code> tag. See
      <code class="command">\pset tableattr</code> for details.
      </p></dd><dt><span class="term"><code class="option">-U <em class="replaceable"><code>username</code></em></code><br /></span><span class="term"><code class="option">--username=<em class="replaceable"><code>username</code></em></code></span></dt><dd><p>
      Connect to the database as the user <em class="replaceable"><code>username</code></em> instead of the default.
      (You must have permission to do so, of course.)
      </p></dd><dt><span class="term"><code class="option">-v <em class="replaceable"><code>assignment</code></em></code><br /></span><span class="term"><code class="option">--set=<em class="replaceable"><code>assignment</code></em></code><br /></span><span class="term"><code class="option">--variable=<em class="replaceable"><code>assignment</code></em></code></span></dt><dd><p>
      Perform a variable assignment, like the <code class="command">\set</code>
      meta-command. Note that you must separate name and value, if
      any, by an equal sign on the command line. To unset a variable,
      leave off the equal sign. To set a variable with an empty value,
      use the equal sign but leave off the value. These assignments are
      done during command line processing, so variables that reflect
      connection state will get overwritten later.
      </p></dd><dt><span class="term"><code class="option">-V</code><br /></span><span class="term"><code class="option">--version</code></span></dt><dd><p>
      Print the <span class="application">psql</span> version and exit.
      </p></dd><dt><span class="term"><code class="option">-w</code><br /></span><span class="term"><code class="option">--no-password</code></span></dt><dd><p>
       Never issue a password prompt.  If the server requires password
       authentication and a password is not available by other means
       such as a <code class="filename">.pgpass</code> file, the connection
       attempt will fail.  This option can be useful in batch jobs and
       scripts where no user is present to enter a password.
      </p><p>
       Note that this option will remain set for the entire session,
       and so it affects uses of the meta-command
       <code class="command">\connect</code> as well as the initial connection attempt.
      </p></dd><dt><span class="term"><code class="option">-W</code><br /></span><span class="term"><code class="option">--password</code></span></dt><dd><p>
       Force <span class="application">psql</span> to prompt for a
       password before connecting to a database.
      </p><p>
       This option is never essential, since <span class="application">psql</span>
       will automatically prompt for a password if the server demands
       password authentication.  However, <span class="application">psql</span>
       will waste a connection attempt finding out that the server wants a
       password.  In some cases it is worth typing <code class="option">-W</code> to avoid
       the extra connection attempt.
      </p><p>
       Note that this option will remain set for the entire session,
       and so it affects uses of the meta-command
       <code class="command">\connect</code> as well as the initial connection attempt.
      </p></dd><dt><span class="term"><code class="option">-x</code><br /></span><span class="term"><code class="option">--expanded</code></span></dt><dd><p>
      Turn on the expanded table formatting mode. This is equivalent to
      <code class="command">\x</code> or <code class="command">\pset expanded</code>.
      </p></dd><dt><span class="term"><code class="option">-X,</code><br /></span><span class="term"><code class="option">--no-psqlrc</code></span></dt><dd><p>
      Do not read the start-up file (neither the system-wide
      <code class="filename">psqlrc</code> file nor the user's
      <code class="filename">~/.psqlrc</code> file).
      </p></dd><dt><span class="term"><code class="option">-z</code><br /></span><span class="term"><code class="option">--field-separator-zero</code></span></dt><dd><p>
      Set the field separator for unaligned output to a zero byte.  This is
      equivalent to <code class="command">\pset fieldsep_zero</code>.
      </p></dd><dt><span class="term"><code class="option">-0</code><br /></span><span class="term"><code class="option">--record-separator-zero</code></span></dt><dd><p>
      Set the record separator for unaligned output to a zero byte.  This is
      useful for interfacing, for example, with <code class="literal">xargs -0</code>.
      This is equivalent to <code class="command">\pset recordsep_zero</code>.
      </p></dd><dt><span class="term"><code class="option">-1</code><br /></span><span class="term"><code class="option">--single-transaction</code></span></dt><dd><p>
        This option can only be used in combination with one or more
        <code class="option">-c</code> and/or <code class="option">-f</code> options.  It causes
        <span class="application">psql</span> to issue a <code class="command">BEGIN</code> command
        before the first such option and a <code class="command">COMMIT</code> command after
        the last one, thereby wrapping all the commands into a single
        transaction.  This ensures that either all the commands complete
        successfully, or no changes are applied.
       </p><p>
        If the commands themselves
        contain <code class="command">BEGIN</code>, <code class="command">COMMIT</code>,
        or <code class="command">ROLLBACK</code>, this option will not have the desired
        effects.  Also, if an individual command cannot be executed inside a
        transaction block, specifying this option will cause the whole
        transaction to fail.
       </p></dd><dt><span class="term"><code class="option">-?</code><br /></span><span class="term"><code class="option">--help[=<em class="replaceable"><code>topic</code></em>]</code></span></dt><dd><p>
      Show help about <span class="application">psql</span> and exit. The optional
      <em class="replaceable"><code>topic</code></em> parameter (defaulting
      to <code class="literal">options</code>) selects which part of <span class="application">psql</span> is
      explained: <code class="literal">commands</code> describes <span class="application">psql</span>'s
      backslash commands; <code class="literal">options</code> describes the command-line
      options that can be passed to <span class="application">psql</span>;
      and <code class="literal">variables</code> shows help about <span class="application">psql</span> configuration
      variables.
      </p></dd></dl></div></div><div class="refsect1" id="id-1.9.4.18.7"><h2>Exit Status</h2><p>
   <span class="application">psql</span> returns 0 to the shell if it
   finished normally, 1 if a fatal error of its own occurs (e.g. out of memory,
   file not found), 2 if the connection to the server went bad
   and the session was not interactive, and 3 if an error occurred in a
   script and the variable <code class="varname">ON_ERROR_STOP</code> was set.
  </p></div><div class="refsect1" id="id-1.9.4.18.8"><h2>Usage</h2><div class="refsect2" id="R2-APP-PSQL-CONNECTING"><h3>Connecting to a Database</h3><p>
    <span class="application">psql</span> is a regular
    <span class="productname">PostgreSQL</span> client application. In order
    to connect to a database you need to know the name of your target
    database, the host name and port number of the server, and what user
    name you want to connect as. <span class="application">psql</span> can be
    told about those parameters via command line options, namely
    <code class="option">-d</code>, <code class="option">-h</code>, <code class="option">-p</code>, and
    <code class="option">-U</code> respectively. If an argument is found that does
    not belong to any option it will be interpreted as the database name
    (or the user name, if the database name is already given). Not all
    of these options are required; there are useful defaults. If you omit the host
    name, <span class="application">psql</span> will connect via a Unix-domain socket
    to a server on the local host, or via TCP/IP to <code class="literal">localhost</code> on
    machines that don't have Unix-domain sockets. The default port number is
    determined at compile time.
    Since the database server uses the same default, you will not have
    to specify the port in most cases. The default user name is your
    operating-system user name, as is the default database name.
    Note that you cannot
    just connect to any database under any user name. Your database
    administrator should have informed you about your access rights.
    </p><p>
    When the defaults aren't quite right, you can save yourself
    some typing by setting the environment variables
    <code class="envar">PGDATABASE</code>, <code class="envar">PGHOST</code>,
    <code class="envar">PGPORT</code> and/or <code class="envar">PGUSER</code> to appropriate
    values. (For additional environment variables, see <a class="xref" href="libpq-envars.html" title="33.14. Environment Variables">Section 33.14</a>.) It is also convenient to have a
    <code class="filename">~/.pgpass</code> file to avoid regularly having to type in
    passwords. See <a class="xref" href="libpq-pgpass.html" title="33.15. The Password File">Section 33.15</a> for more information.
    </p><p>
     An alternative way to specify connection parameters is in a
     <em class="parameter"><code>conninfo</code></em> string or
     a <acronym class="acronym">URI</acronym>, which is used instead of a database
     name. This mechanism give you very wide control over the
     connection. For example:
</p><pre class="programlisting">
$ <strong class="userinput"><code>psql "service=myservice sslmode=require"</code></strong>
$ <strong class="userinput"><code>psql postgresql://dbmaster:5433/mydb?sslmode=require</code></strong>
</pre><p>
     This way you can also use <acronym class="acronym">LDAP</acronym> for connection
     parameter lookup as described in <a class="xref" href="libpq-ldap.html" title="33.17. LDAP Lookup of Connection Parameters">Section 33.17</a>.
     See <a class="xref" href="libpq-connect.html#LIBPQ-PARAMKEYWORDS" title="33.1.2. Parameter Key Words">Section 33.1.2</a> for more information on all the
     available connection options.
    </p><p>
    If the connection could not be made for any reason (e.g., insufficient
    privileges, server is not running on the targeted host, etc.),
    <span class="application">psql</span> will return an error and terminate.
    </p><p>
     If both standard input and standard output are a
     terminal, then <span class="application">psql</span> sets the client
     encoding to <span class="quote">“<span class="quote">auto</span>”</span>, which will detect the
     appropriate client encoding from the locale settings
     (<code class="envar">LC_CTYPE</code> environment variable on Unix systems).
     If this doesn't work out as expected, the client encoding can be
     overridden using the environment
     variable <code class="envar">PGCLIENTENCODING</code>.
    </p></div><div class="refsect2" id="R2-APP-PSQL-4"><h3>Entering SQL Commands</h3><p>
    In normal operation, <span class="application">psql</span> provides a
    prompt with the name of the database to which
    <span class="application">psql</span> is currently connected, followed by
    the string <code class="literal">=&gt;</code>. For example:
</p><pre class="programlisting">
$ <strong class="userinput"><code>psql testdb</code></strong>
psql (12.4)
Type "help" for help.

testdb=&gt;
</pre><p>
    </p><p>
    At the prompt, the user can type in <acronym class="acronym">SQL</acronym> commands.
    Ordinarily, input lines are sent to the server when a
    command-terminating semicolon is reached. An end of line does not
    terminate a command.  Thus commands can be spread over several lines for
    clarity. If the command was sent and executed without error, the results
    of the command are displayed on the screen.
    </p><p>
    If untrusted users have access to a database that has not adopted a
    <a class="link" href="ddl-schemas.html#DDL-SCHEMAS-PATTERNS" title="5.9.6. Usage Patterns">secure schema usage pattern</a>,
    begin your session by removing publicly-writable schemas
    from <code class="varname">search_path</code>.  One can
    add <code class="literal">options=-csearch_path=</code> to the connection string or
    issue <code class="literal">SELECT pg_catalog.set_config('search_path', '',
    false)</code> before other SQL commands.  This consideration is not
    specific to <span class="application">psql</span>; it applies to every interface
    for executing arbitrary SQL commands.
    </p><p>
    Whenever a command is executed, <span class="application">psql</span> also polls
    for asynchronous notification events generated by
    <a class="xref" href="sql-listen.html" title="LISTEN"><span class="refentrytitle">LISTEN</span></a> and
    <a class="xref" href="sql-notify.html" title="NOTIFY"><span class="refentrytitle">NOTIFY</span></a>.
    </p><p>
    While C-style block comments are passed to the server for
    processing and removal, SQL-standard comments are removed by
    <span class="application">psql</span>.
    </p></div><div class="refsect2" id="APP-PSQL-META-COMMANDS"><h3>Meta-Commands</h3><p>
    Anything you enter in <span class="application">psql</span> that begins
    with an unquoted backslash is a <span class="application">psql</span>
    meta-command that is processed by <span class="application">psql</span>
    itself. These commands make
    <span class="application">psql</span> more useful for administration or
    scripting. Meta-commands are often called slash or backslash commands.
    </p><p>
    The format of a <span class="application">psql</span> command is the backslash,
    followed immediately by a command verb, then any arguments. The arguments
    are separated from the command verb and each other by any number of
    whitespace characters.
    </p><p>
    To include whitespace in an argument you can quote it with
    single quotes. To include a single quote in an argument,
    write two single quotes within single-quoted text.
    Anything contained in single quotes is
    furthermore subject to C-like substitutions for
    <code class="literal">\n</code> (new line), <code class="literal">\t</code> (tab),
    <code class="literal">\b</code> (backspace), <code class="literal">\r</code> (carriage return),
    <code class="literal">\f</code> (form feed),
    <code class="literal">\</code><em class="replaceable"><code>digits</code></em> (octal), and
    <code class="literal">\x</code><em class="replaceable"><code>digits</code></em> (hexadecimal).
    A backslash preceding any other character within single-quoted text
    quotes that single character, whatever it is.
    </p><p>
    If an unquoted colon (<code class="literal">:</code>) followed by a
    <span class="application">psql</span> variable name appears within an argument, it is
    replaced by the variable's value, as described in <a class="xref" href="app-psql.html#APP-PSQL-INTERPOLATION" title="SQL Interpolation"><acronym class="acronym">SQL</acronym> Interpolation</a>.
    The forms <code class="literal">:'<em class="replaceable"><code>variable_name</code></em>'</code> and
    <code class="literal">:"<em class="replaceable"><code>variable_name</code></em>"</code> described there
    work as well.
    The <code class="literal">:{?<em class="replaceable"><code>variable_name</code></em>}</code> syntax allows
    testing whether a variable is defined. It is substituted by
    TRUE or FALSE.
    Escaping the colon with a backslash protects it from substitution.
    </p><p>
    Within an argument, text that is enclosed in backquotes
    (<code class="literal">`</code>) is taken as a command line that is passed to the
    shell.  The output of the command (with any trailing newline removed)
    replaces the backquoted text.  Within the text enclosed in backquotes,
    no special quoting or other processing occurs, except that appearances
    of <code class="literal">:<em class="replaceable"><code>variable_name</code></em></code> where
    <em class="replaceable"><code>variable_name</code></em> is a <span class="application">psql</span> variable name
    are replaced by the variable's value.  Also, appearances of
    <code class="literal">:'<em class="replaceable"><code>variable_name</code></em>'</code> are replaced by the
    variable's value suitably quoted to become a single shell command
    argument.  (The latter form is almost always preferable, unless you are
    very sure of what is in the variable.)  Because carriage return and line
    feed characters cannot be safely quoted on all platforms, the
    <code class="literal">:'<em class="replaceable"><code>variable_name</code></em>'</code> form prints an
    error message and does not substitute the variable value when such
    characters appear in the value.
    </p><p>
    Some commands take an <acronym class="acronym">SQL</acronym> identifier (such as a
    table name) as argument. These arguments follow the syntax rules
    of <acronym class="acronym">SQL</acronym>: Unquoted letters are forced to
    lowercase, while double quotes (<code class="literal">"</code>) protect letters
    from case conversion and allow incorporation of whitespace into
    the identifier.  Within double quotes, paired double quotes reduce
    to a single double quote in the resulting name.  For example,
    <code class="literal">FOO"BAR"BAZ</code> is interpreted as <code class="literal">fooBARbaz</code>,
    and <code class="literal">"A weird"" name"</code> becomes <code class="literal">A weird"
    name</code>.
    </p><p>
    Parsing for arguments stops at the end of the line, or when another
    unquoted backslash is found.  An unquoted backslash
    is taken as the beginning of a new meta-command. The special
    sequence <code class="literal">\\</code> (two backslashes) marks the end of
    arguments and continues parsing <acronym class="acronym">SQL</acronym> commands, if
    any. That way <acronym class="acronym">SQL</acronym> and
    <span class="application">psql</span> commands can be freely mixed on a
    line. But in any case, the arguments of a meta-command cannot
    continue beyond the end of the line.
    </p><p>
    Many of the meta-commands act on the <em class="firstterm">current query buffer</em>.
    This is simply a buffer holding whatever SQL command text has been typed
    but not yet sent to the server for execution.  This will include previous
    input lines as well as any text appearing before the meta-command on the
    same line.
    </p><p>
    The following meta-commands are defined:

    </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">\a</code></span></dt><dd><p>
        If the current table output format is unaligned, it is switched to aligned.
        If it is not unaligned, it is set to unaligned. This command is
        kept for backwards compatibility. See <code class="command">\pset</code> for a
        more general solution.
        </p></dd><dt><span class="term"><code class="literal">\c</code> or <code class="literal">\connect [ -reuse-previous=<em class="replaceable"><code>on|off</code></em> ] [ <em class="replaceable"><code>dbname</code></em> [ <em class="replaceable"><code>username</code></em> ] [ <em class="replaceable"><code>host</code></em> ] [ <em class="replaceable"><code>port</code></em> ] | <em class="replaceable"><code>conninfo</code></em> ]</code></span></dt><dd><p>
        Establishes a new connection to a <span class="productname">PostgreSQL</span>
        server.  The connection parameters to use can be specified either
        using a positional syntax, or using <em class="replaceable"><code>conninfo</code></em> connection
        strings as detailed in <a class="xref" href="libpq-connect.html#LIBPQ-CONNSTRING" title="33.1.1. Connection Strings">Section 33.1.1</a>.
        </p><p>
        Where the command omits database name, user, host, or port, the new
        connection can reuse values from the previous connection.  By default,
        values from the previous connection are reused except when processing
        a <em class="replaceable"><code>conninfo</code></em> string.  Passing a first argument
        of <code class="literal">-reuse-previous=on</code>
        or <code class="literal">-reuse-previous=off</code> overrides that default.
        When the command neither specifies nor reuses a particular parameter,
        the <span class="application">libpq</span> default is used.  Specifying any
        of <em class="replaceable"><code>dbname</code></em>,
        <em class="replaceable"><code>username</code></em>,
        <em class="replaceable"><code>host</code></em> or
        <em class="replaceable"><code>port</code></em>
        as <code class="literal">-</code> is equivalent to omitting that parameter.
        If <code class="literal">hostaddr</code> was specified in the original
        connection's <code class="structname">conninfo</code>, that address is reused
        for the new connection (disregarding any other host specification).
        </p><p>
        If the new connection is successfully made, the previous
        connection is closed.
        If the connection attempt failed (wrong user name, access
        denied, etc.), the previous connection will only be kept if
        <span class="application">psql</span> is in interactive mode. When
        executing a non-interactive script, processing will
        immediately stop with an error. This distinction was chosen as
        a user convenience against typos on the one hand, and a safety
        mechanism that scripts are not accidentally acting on the
        wrong database on the other hand.
        </p><p>
        Examples:
        </p><pre class="programlisting">
=&gt; \c mydb myuser host.dom 6432
=&gt; \c service=foo
=&gt; \c "host=localhost port=5432 dbname=mydb connect_timeout=10 sslmode=disable"
=&gt; \c postgresql://tom@localhost/mydb?application_name=myapp
</pre></dd><dt><span class="term"><code class="literal">\C [ <em class="replaceable"><code>title</code></em> ]</code></span></dt><dd><p>
        Sets the title of any tables being printed as the result of a
        query or unset any such title. This command is equivalent to
        <code class="literal">\pset title <em class="replaceable"><code>title</code></em></code>. (The name of
        this command derives from <span class="quote">“<span class="quote">caption</span>”</span>, as it was
        previously only used to set the caption in an
        <acronym class="acronym">HTML</acronym> table.)
        </p></dd><dt><span class="term"><code class="literal">\cd [ <em class="replaceable"><code>directory</code></em> ]</code></span></dt><dd><p>
         Changes the current working directory to
         <em class="replaceable"><code>directory</code></em>. Without argument, changes
         to the current user's home directory.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
          To print your current working directory, use <code class="literal">\! pwd</code>.
         </p></div></dd><dt><span class="term"><code class="literal">\conninfo</code></span></dt><dd><p>
        Outputs information about the current database connection.
        </p></dd><dt id="APP-PSQL-META-COMMANDS-COPY"><span class="term"><code class="literal">\copy { <em class="replaceable"><code>table</code></em> [ ( <em class="replaceable"><code>column_list</code></em> ) ] }
        <code class="literal">from</code>
        { <em class="replaceable"><code>'filename'</code></em> | program <em class="replaceable"><code>'command'</code></em> | stdin | pstdin }
        [ [ with ] ( <em class="replaceable"><code>option</code></em> [, ...] ) ]
        [ where <em class="replaceable"><code>condition</code></em> ]</code><br /></span><span class="term"><code class="literal">\copy { <em class="replaceable"><code>table</code></em> [ ( <em class="replaceable"><code>column_list</code></em> ) ] | ( <em class="replaceable"><code>query</code></em> ) }
        <code class="literal">to</code>
        { <em class="replaceable"><code>'filename'</code></em> | program <em class="replaceable"><code>'command'</code></em> | stdout | pstdout }
        [ [ with ] ( <em class="replaceable"><code>option</code></em> [, ...] ) ]</code></span></dt><dd><p>
        Performs a frontend (client) copy. This is an operation that
        runs an <acronym class="acronym">SQL</acronym> <a class="xref" href="sql-copy.html" title="COPY"><span class="refentrytitle">COPY</span></a>
        command, but instead of the server
        reading or writing the specified file,
        <span class="application">psql</span> reads or writes the file and
        routes the data between the server and the local file system.
        This means that file accessibility and privileges are those of
        the local user, not the server, and no SQL superuser
        privileges are required.
        </p><p>
        When <code class="literal">program</code> is specified,
        <em class="replaceable"><code>command</code></em> is
        executed by <span class="application">psql</span> and the data passed from
        or to <em class="replaceable"><code>command</code></em> is
        routed between the server and the client.
        Again, the execution privileges are those of
        the local user, not the server, and no SQL superuser
        privileges are required.
        </p><p>
        For <code class="literal">\copy ... from stdin</code>, data rows are read from the same
        source that issued the command, continuing until <code class="literal">\.</code>
        is read or the stream reaches <acronym class="acronym">EOF</acronym>. This option is useful
        for populating tables in-line within a SQL script file.
        For <code class="literal">\copy ... to stdout</code>, output is sent to the same place
        as <span class="application">psql</span> command output, and
        the <code class="literal">COPY <em class="replaceable"><code>count</code></em></code> command status is
        not printed (since it might be confused with a data row).
        To read/write <span class="application">psql</span>'s standard input or
        output regardless of the current command source or <code class="literal">\o</code>
        option, write <code class="literal">from pstdin</code> or <code class="literal">to pstdout</code>.
        </p><p>
        The syntax of this command is similar to that of the
        <acronym class="acronym">SQL</acronym> <a class="xref" href="sql-copy.html" title="COPY"><span class="refentrytitle">COPY</span></a>
        command.  All options other than the data source/destination are
        as specified for <a class="xref" href="sql-copy.html" title="COPY"><span class="refentrytitle">COPY</span></a>.
        Because of this, special parsing rules apply to the <code class="command">\copy</code>
        meta-command.  Unlike most other meta-commands, the entire remainder
        of the line is always taken to be the arguments of <code class="command">\copy</code>,
        and neither variable interpolation nor backquote expansion are
        performed in the arguments.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        Another way to obtain the same result as <code class="literal">\copy
        ... to</code> is to use the <acronym class="acronym">SQL</acronym> <code class="literal">COPY
        ... TO STDOUT</code> command and terminate it
        with <code class="literal">\g <em class="replaceable"><code>filename</code></em></code>
        or <code class="literal">\g |<em class="replaceable"><code>program</code></em></code>.
        Unlike <code class="literal">\copy</code>, this method allows the command to
        span multiple lines; also, variable interpolation and backquote
        expansion can be used.
        </p></div><div class="tip"><h3 class="title">Tip</h3><p>
        These operations are not as efficient as the <acronym class="acronym">SQL</acronym>
        <code class="command">COPY</code> command with a file or program data source or
        destination, because all data must pass through the client/server
        connection.  For large amounts of data the <acronym class="acronym">SQL</acronym>
        command might be preferable.
        </p></div></dd><dt><span class="term"><code class="literal">\copyright</code></span></dt><dd><p>
        Shows the copyright and distribution terms of
        <span class="productname">PostgreSQL</span>.
        </p></dd><dt id="APP-PSQL-META-COMMANDS-CROSSTABVIEW"><span class="term"><code class="literal">\crosstabview [
            <em class="replaceable"><code>colV</code></em>
            [ <em class="replaceable"><code>colH</code></em>
            [ <em class="replaceable"><code>colD</code></em>
            [ <em class="replaceable"><code>sortcolH</code></em>
            ] ] ] ] </code></span></dt><dd><p>
        Executes the current query buffer (like <code class="literal">\g</code>) and
        shows the results in a crosstab grid.
        The query must return at least three columns.
        The output column identified by <em class="replaceable"><code>colV</code></em>
        becomes a vertical header and the output column identified by
        <em class="replaceable"><code>colH</code></em>
        becomes a horizontal header.
        <em class="replaceable"><code>colD</code></em> identifies
        the output column to display within the grid.
        <em class="replaceable"><code>sortcolH</code></em> identifies
        an optional sort column for the horizontal header.
        </p><p>
        Each column specification can be a column number (starting at 1) or
        a column name.  The usual SQL case folding and quoting rules apply to
        column names.  If omitted,
        <em class="replaceable"><code>colV</code></em> is taken as column 1
        and <em class="replaceable"><code>colH</code></em> as column 2.
        <em class="replaceable"><code>colH</code></em> must differ from
        <em class="replaceable"><code>colV</code></em>.
        If <em class="replaceable"><code>colD</code></em> is not
        specified, then there must be exactly three columns in the query
        result, and the column that is neither
        <em class="replaceable"><code>colV</code></em> nor
        <em class="replaceable"><code>colH</code></em>
        is taken to be <em class="replaceable"><code>colD</code></em>.
        </p><p>
        The vertical header, displayed as the leftmost column, contains the
        values found in column <em class="replaceable"><code>colV</code></em>, in the
        same order as in the query results, but with duplicates removed.
        </p><p>
        The horizontal header, displayed as the first row, contains the values
        found in column <em class="replaceable"><code>colH</code></em>,
        with duplicates removed.  By default, these appear in the same order
        as in the query results.  But if the
        optional <em class="replaceable"><code>sortcolH</code></em> argument is given,
        it identifies a column whose values must be integer numbers, and the
        values from <em class="replaceable"><code>colH</code></em> will
        appear in the horizontal header sorted according to the
        corresponding <em class="replaceable"><code>sortcolH</code></em> values.
        </p><p>
        Inside the crosstab grid, for each distinct value <code class="literal">x</code>
        of <em class="replaceable"><code>colH</code></em> and each distinct
        value <code class="literal">y</code>
        of <em class="replaceable"><code>colV</code></em>, the cell located
        at the intersection <code class="literal">(x,y)</code> contains the value of
        the <code class="literal">colD</code> column in the query result row for which
        the value of <em class="replaceable"><code>colH</code></em>
        is <code class="literal">x</code> and the value
        of <em class="replaceable"><code>colV</code></em>
        is <code class="literal">y</code>.  If there is no such row, the cell is empty.  If
        there are multiple such rows, an error is reported.
        </p></dd><dt><span class="term"><code class="literal">\d[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        For each relation (table, view, materialized view, index, sequence,
        or foreign table)
        or composite type matching the
        <em class="replaceable"><code>pattern</code></em>, show all
        columns, their types, the tablespace (if not the default) and any
        special attributes such as <code class="literal">NOT NULL</code> or defaults.
        Associated indexes, constraints, rules, and triggers are
        also shown.  For foreign tables, the associated foreign
        server is shown as well.
        (<span class="quote">“<span class="quote">Matching the pattern</span>”</span> is defined in
        <a class="xref" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns">Patterns</a>
        below.)
        </p><p>
        For some types of relation, <code class="literal">\d</code> shows additional information
        for each column: column values for sequences, indexed expressions for
        indexes, and foreign data wrapper options for foreign tables.
        </p><p>
        The command form <code class="literal">\d+</code> is identical, except that
        more information is displayed: any comments associated with the
        columns of the table are shown, as is the presence of OIDs in the
        table, the view definition if the relation is a view, a non-default
        <a class="link" href="sql-altertable.html#SQL-CREATETABLE-REPLICA-IDENTITY">replica
        identity</a> setting.
        </p><p>
        By default, only user-created objects are shown;  supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        </p><div class="note"><h3 class="title">Note</h3><p>
        If <code class="command">\d</code> is used without a
        <em class="replaceable"><code>pattern</code></em> argument, it is
        equivalent to <code class="command">\dtvmsE</code> which will show a list of
        all visible tables, views, materialized views, sequences and
        foreign tables.
        This is purely a convenience measure.
        </p></div></dd><dt><span class="term"><code class="literal">\da[S] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists aggregate functions, together with their
        return type and the data types they operate on. If <em class="replaceable"><code>pattern</code></em>
        is specified, only aggregates whose names match the pattern are shown.
        By default, only user-created objects are shown;  supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        </p></dd><dt><span class="term"><code class="literal">\dA[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists access methods. If <em class="replaceable"><code>pattern</code></em> is specified, only access
        methods whose names match the pattern are shown. If
        <code class="literal">+</code> is appended to the command name, each access
        method is listed with its associated handler function and description.
        </p></dd><dt><span class="term"><code class="literal">\db[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists tablespaces. If <em class="replaceable"><code>pattern</code></em>
        is specified, only tablespaces whose names match the pattern are shown.
        If <code class="literal">+</code> is appended to the command name, each tablespace
        is listed with its associated options, on-disk size, permissions and
        description.
        </p></dd><dt><span class="term"><code class="literal">\dc[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists conversions between character-set encodings.
        If <em class="replaceable"><code>pattern</code></em>
        is specified, only conversions whose names match the pattern are
        listed.
        By default, only user-created objects are shown;  supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        If <code class="literal">+</code> is appended to the command name, each object
        is listed with its associated description.
        </p></dd><dt><span class="term"><code class="literal">\dC[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists type casts.
        If <em class="replaceable"><code>pattern</code></em>
        is specified, only casts whose source or target types match the
        pattern are listed.
        If <code class="literal">+</code> is appended to the command name, each object
        is listed with its associated description.
        </p></dd><dt><span class="term"><code class="literal">\dd[S] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Shows the descriptions of objects of type <code class="literal">constraint</code>,
        <code class="literal">operator class</code>, <code class="literal">operator family</code>,
        <code class="literal">rule</code>, and <code class="literal">trigger</code>. All
        other comments may be viewed by the respective backslash commands for
        those object types.
        </p><p><code class="literal">\dd</code> displays descriptions for objects matching the
        <em class="replaceable"><code>pattern</code></em>, or of visible
        objects of the appropriate type if no argument is given.  But in either
        case, only objects that have a description are listed.
        By default, only user-created objects are shown;  supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        </p><p>
        Descriptions for objects can be created with the <a class="xref" href="sql-comment.html" title="COMMENT"><span class="refentrytitle">COMMENT</span></a>
        <acronym class="acronym">SQL</acronym> command.
       </p></dd><dt><span class="term"><code class="literal">\dD[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists domains. If <em class="replaceable"><code>pattern</code></em>
        is specified, only domains whose names match the pattern are shown.
        By default, only user-created objects are shown;  supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        If <code class="literal">+</code> is appended to the command name, each object
        is listed with its associated permissions and description.
        </p></dd><dt><span class="term"><code class="literal">\ddp [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists default access privilege settings.  An entry is shown for
        each role (and schema, if applicable) for which the default
        privilege settings have been changed from the built-in defaults.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only entries whose role name or schema name matches
        the pattern are listed.
        </p><p>
        The <a class="xref" href="sql-alterdefaultprivileges.html" title="ALTER DEFAULT PRIVILEGES"><span class="refentrytitle">ALTER DEFAULT PRIVILEGES</span></a> command is used to set
        default access privileges.  The meaning of the
        privilege display is explained in
        <a class="xref" href="ddl-priv.html" title="5.7. Privileges">Section 5.7</a>.
        </p></dd><dt><span class="term"><code class="literal">\dE[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code><br /></span><span class="term"><code class="literal">\di[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code><br /></span><span class="term"><code class="literal">\dm[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code><br /></span><span class="term"><code class="literal">\ds[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code><br /></span><span class="term"><code class="literal">\dt[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code><br /></span><span class="term"><code class="literal">\dv[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        In this group of commands, the letters <code class="literal">E</code>,
        <code class="literal">i</code>, <code class="literal">m</code>, <code class="literal">s</code>,
        <code class="literal">t</code>, and <code class="literal">v</code>
        stand for foreign table, index, materialized view, sequence, table, and view,
        respectively.
        You can specify any or all of
        these letters, in any order, to obtain a listing of objects
        of these types.  For example, <code class="literal">\dit</code> lists indexes
        and tables.  If <code class="literal">+</code> is
        appended to the command name, each object is listed with its
        physical size on disk and its associated description, if any.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only objects whose names match the pattern are listed.
        By default, only user-created objects are shown; supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        </p></dd><dt><span class="term"><code class="literal">\des[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists foreign servers (mnemonic: <span class="quote">“<span class="quote">external
        servers</span>”</span>).
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only those servers whose name matches the pattern
        are listed.  If the form <code class="literal">\des+</code> is used, a
        full description of each server is shown, including the
        server's access privileges, type, version, options, and description.
        </p></dd><dt><span class="term"><code class="literal">\det[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists foreign tables (mnemonic: <span class="quote">“<span class="quote">external tables</span>”</span>).
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only entries whose table name or schema name matches
        the pattern are listed.  If the form <code class="literal">\det+</code>
        is used, generic options and the foreign table description
        are also displayed.
        </p></dd><dt><span class="term"><code class="literal">\deu[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists user mappings (mnemonic: <span class="quote">“<span class="quote">external
        users</span>”</span>).
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only those mappings whose user names match the
        pattern are listed.  If the form <code class="literal">\deu+</code> is
        used, additional information about each mapping is shown.
        </p><div class="caution"><h3 class="title">Caution</h3><p>
        <code class="literal">\deu+</code> might also display the user name and
        password of the remote user, so care should be taken not to
        disclose them.
        </p></div></dd><dt><span class="term"><code class="literal">\dew[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists foreign-data wrappers (mnemonic: <span class="quote">“<span class="quote">external
        wrappers</span>”</span>).
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only those foreign-data wrappers whose name matches
        the pattern are listed.  If the form <code class="literal">\dew+</code>
        is used, the access privileges, options, and description of the
        foreign-data wrapper are also shown.
        </p></dd><dt><span class="term"><code class="literal">\df[anptwS+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists functions, together with their result data types, argument data
        types, and function types, which are classified as <span class="quote">“<span class="quote">agg</span>”</span>
        (aggregate), <span class="quote">“<span class="quote">normal</span>”</span>, <span class="quote">“<span class="quote">procedure</span>”</span>, <span class="quote">“<span class="quote">trigger</span>”</span>, or <span class="quote">“<span class="quote">window</span>”</span>.
        To display only functions
        of specific type(s), add the corresponding letters <code class="literal">a</code>,
        <code class="literal">n</code>, <code class="literal">p</code>, <code class="literal">t</code>, or <code class="literal">w</code> to the command.
        If <em class="replaceable"><code>pattern</code></em> is specified, only
        functions whose names match the pattern are shown.
        By default, only user-created
        objects are shown; supply a pattern or the <code class="literal">S</code>
        modifier to include system objects.
        If the form <code class="literal">\df+</code> is used, additional information
        about each function is shown, including volatility,
        parallel safety, owner, security classification, access privileges,
        language, source code and description.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        To look up functions taking arguments or returning values of a specific
        data type, use your pager's search capability to scroll through the
        <code class="literal">\df</code> output.
        </p></div></dd><dt><span class="term"><code class="literal">\dF[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
         Lists text search configurations.
         If <em class="replaceable"><code>pattern</code></em> is specified,
         only configurations whose names match the pattern are shown.
         If the form <code class="literal">\dF+</code> is used, a full description of
         each configuration is shown, including the underlying text search
         parser and the dictionary list for each parser token type.
        </p></dd><dt><span class="term"><code class="literal">\dFd[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
         Lists text search dictionaries.
         If <em class="replaceable"><code>pattern</code></em> is specified,
         only dictionaries whose names match the pattern are shown.
         If the form <code class="literal">\dFd+</code> is used, additional information
         is shown about each selected dictionary, including the underlying
         text search template and the option values.
        </p></dd><dt><span class="term"><code class="literal">\dFp[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
         Lists text search parsers.
         If <em class="replaceable"><code>pattern</code></em> is specified,
         only parsers whose names match the pattern are shown.
         If the form <code class="literal">\dFp+</code> is used, a full description of
         each parser is shown, including the underlying functions and the
         list of recognized token types.
        </p></dd><dt><span class="term"><code class="literal">\dFt[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
         Lists text search templates.
         If <em class="replaceable"><code>pattern</code></em> is specified,
         only templates whose names match the pattern are shown.
         If the form <code class="literal">\dFt+</code> is used, additional information
         is shown about each template, including the underlying function names.
        </p></dd><dt><span class="term"><code class="literal">\dg[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists database roles.
        (Since the concepts of <span class="quote">“<span class="quote">users</span>”</span> and <span class="quote">“<span class="quote">groups</span>”</span> have been
        unified into <span class="quote">“<span class="quote">roles</span>”</span>, this command is now equivalent to
        <code class="literal">\du</code>.)
        By default, only user-created roles are shown; supply the
        <code class="literal">S</code> modifier to include system roles.
        If <em class="replaceable"><code>pattern</code></em> is specified,
        only those roles whose names match the pattern are listed.
        If the form <code class="literal">\dg+</code> is used, additional information
        is shown about each role; currently this adds the comment for each
        role.
        </p></dd><dt><span class="term"><code class="literal">\dl</code></span></dt><dd><p>
        This is an alias for <code class="command">\lo_list</code>, which shows a
        list of large objects.
        </p></dd><dt><span class="term"><code class="literal">\dL[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists procedural languages. If <em class="replaceable"><code>pattern</code></em>
        is specified, only languages whose names match the pattern are listed.
        By default, only user-created languages
        are shown; supply the <code class="literal">S</code> modifier to include system
        objects. If <code class="literal">+</code> is appended to the command name, each
        language is listed with its call handler, validator, access privileges,
        and whether it is a system object.
        </p></dd><dt><span class="term"><code class="literal">\dn[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists schemas (namespaces). If <em class="replaceable"><code>pattern</code></em>
        is specified, only schemas whose names match the pattern are listed.
        By default, only user-created objects are shown; supply a
        pattern or the <code class="literal">S</code> modifier to include system objects.
        If <code class="literal">+</code> is appended to the command name, each object
        is listed with its associated permissions and description, if any.
        </p></dd><dt><span class="term"><code class="literal">\do[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists operators with their operand and result types.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only operators whose names match the pattern are listed.
        By default, only user-created objects are shown; supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        If <code class="literal">+</code> is appended to the command name,
        additional information about each operator is shown, currently just
        the name of the underlying function.
        </p></dd><dt><span class="term"><code class="literal">\dO[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists collations.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only collations whose names match the pattern are
        listed.  By default, only user-created objects are shown;
        supply a pattern or the <code class="literal">S</code> modifier to
        include system objects.  If <code class="literal">+</code> is appended
        to the command name, each collation is listed with its associated
        description, if any.
        Note that only collations usable with the current database's encoding
        are shown, so the results may vary in different databases of the
        same installation.
        </p></dd><dt><span class="term"><code class="literal">\dp [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists tables, views and sequences with their
        associated access privileges.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only tables, views and sequences whose names match the
        pattern are listed.
        </p><p>
        The <a class="xref" href="sql-grant.html" title="GRANT"><span class="refentrytitle">GRANT</span></a> and
        <a class="xref" href="sql-revoke.html" title="REVOKE"><span class="refentrytitle">REVOKE</span></a>
        commands are used to set access privileges.  The meaning of the
        privilege display is explained in
        <a class="xref" href="ddl-priv.html" title="5.7. Privileges">Section 5.7</a>.
        </p></dd><dt><span class="term"><code class="literal">\dP[itn+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists partitioned relations.
        If <em class="replaceable"><code>pattern</code></em>
        is specified, only entries whose name matches the pattern are listed.
        The modifiers <code class="literal">t</code> (tables) and <code class="literal">i</code>
        (indexes) can be appended to the command, filtering the kind of
        relations to list.  By default, partitioned tables and indexes are
        listed.
        </p><p>
        If the modifier <code class="literal">n</code> (<span class="quote">“<span class="quote">nested</span>”</span>) is used,
        or a pattern is specified, then non-root partitioned relations are
        included, and a column is shown displaying the parent of each
        partitioned relation.
        </p><p>
        If <code class="literal">+</code> is appended to the command name, the sum of the
        sizes of each relation's partitions is also displayed, along with the
        relation's description.
        If <code class="literal">n</code> is combined with <code class="literal">+</code>, two
        sizes are shown: one including the total size of directly-attached
        leaf partitions, and another showing the total size of all partitions,
        including indirectly attached sub-partitions.
        </p></dd><dt><span class="term"><code class="literal">\drds [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>role-pattern</code></em></a> [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>database-pattern</code></em></a> ] ]</code></span></dt><dd><p>
        Lists defined configuration settings.  These settings can be
        role-specific, database-specific, or both.
        <em class="replaceable"><code>role-pattern</code></em> and
        <em class="replaceable"><code>database-pattern</code></em> are used to select
        specific roles and databases to list, respectively.  If omitted, or if
        <code class="literal">*</code> is specified, all settings are listed, including those
        not role-specific or database-specific, respectively.
        </p><p>
        The <a class="xref" href="sql-alterrole.html" title="ALTER ROLE"><span class="refentrytitle">ALTER ROLE</span></a> and
        <a class="xref" href="sql-alterdatabase.html" title="ALTER DATABASE"><span class="refentrytitle">ALTER DATABASE</span></a>
        commands are used to define per-role and per-database configuration
        settings.
        </p></dd><dt><span class="term"><code class="literal">\dRp[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists replication publications.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only those publications whose names match the pattern are
        listed.
        If <code class="literal">+</code> is appended to the command name, the tables
        associated with each publication are shown as well.
        </p></dd><dt><span class="term"><code class="literal">\dRs[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists replication subscriptions.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only those subscriptions whose names match the pattern are
        listed.
        If <code class="literal">+</code> is appended to the command name, additional
        properties of the subscriptions are shown.
        </p></dd><dt><span class="term"><code class="literal">\dT[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists data types.
        If <em class="replaceable"><code>pattern</code></em> is
        specified, only types whose names match the pattern are listed.
        If <code class="literal">+</code> is appended to the command name, each type is
        listed with its internal name and size, its allowed values
        if it is an <code class="type">enum</code> type, and its associated permissions.
        By default, only user-created objects are shown;  supply a
        pattern or the <code class="literal">S</code> modifier to include system
        objects.
        </p></dd><dt><span class="term"><code class="literal">\du[S+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists database roles.
        (Since the concepts of <span class="quote">“<span class="quote">users</span>”</span> and <span class="quote">“<span class="quote">groups</span>”</span> have been
        unified into <span class="quote">“<span class="quote">roles</span>”</span>, this command is now equivalent to
        <code class="literal">\dg</code>.)
        By default, only user-created roles are shown; supply the
        <code class="literal">S</code> modifier to include system roles.
        If <em class="replaceable"><code>pattern</code></em> is specified,
        only those roles whose names match the pattern are listed.
        If the form <code class="literal">\du+</code> is used, additional information
        is shown about each role; currently this adds the comment for each
        role.
        </p></dd><dt><span class="term"><code class="literal">\dx[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists installed extensions.
        If <em class="replaceable"><code>pattern</code></em>
        is specified, only those extensions whose names match the pattern
        are listed.
        If the form <code class="literal">\dx+</code> is used, all the objects belonging
        to each matching extension are listed.
        </p></dd><dt><span class="term"><code class="literal">\dy[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists event triggers.
        If <em class="replaceable"><code>pattern</code></em>
        is specified, only those event triggers whose names match the pattern
        are listed.
        If <code class="literal">+</code> is appended to the command name, each object
        is listed with its associated description.
        </p></dd><dt><span class="term"><code class="literal">\e</code> or <code class="literal">\edit</code> <code class="literal"> [<span class="optional"> <em class="replaceable"><code>filename</code></em> </span>] [<span class="optional"> <em class="replaceable"><code>line_number</code></em> </span>] </code></span></dt><dd><p>
        If <em class="replaceable"><code>filename</code></em> is
        specified, the file is edited; after the editor exits, the file's
        content is copied into the current query buffer. If no <em class="replaceable"><code>filename</code></em> is given, the current query
        buffer is copied to a temporary file which is then edited in the same
        fashion.  Or, if the current query buffer is empty, the most recently
        executed query is copied to a temporary file and edited in the same
        fashion.
        </p><p>
        The new contents of the query buffer are then re-parsed according to
        the normal rules of <span class="application">psql</span>, treating the
        whole buffer as a single line.  Any complete queries are immediately
        executed; that is, if the query buffer contains or ends with a
        semicolon, everything up to that point is executed.  Whatever remains
        will wait in the query buffer; type semicolon or <code class="literal">\g</code> to
        send it, or <code class="literal">\r</code> to cancel it by clearing the query buffer.
        Treating the buffer as a single line primarily affects meta-commands:
        whatever is in the buffer after a meta-command will be taken as
        argument(s) to the meta-command, even if it spans multiple lines.
        (Thus you cannot make meta-command-using scripts this way.
        Use <code class="command">\i</code> for that.)
        </p><p>
        If a line number is specified, <span class="application">psql</span> will
        position the cursor on the specified line of the file or query buffer.
        Note that if a single all-digits argument is given,
        <span class="application">psql</span> assumes it is a line number,
        not a file name.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        See under <a class="xref" href="app-psql.html#APP-PSQL-ENVIRONMENT" title="Environment">Environment</a> for how to configure and
        customize your editor.
        </p></div></dd><dt><span class="term"><code class="literal">\echo <em class="replaceable"><code>text</code></em> [ ... ]</code></span></dt><dd><p>
        Prints the arguments to the standard output, separated by one
        space and followed by a newline. This can be useful to
        intersperse information in the output of scripts. For example:
</p><pre class="programlisting">
=&gt; <strong class="userinput"><code>\echo `date`</code></strong>
Tue Oct 26 21:40:57 CEST 1999
</pre><p>
        If the first argument is an unquoted <code class="literal">-n</code> the trailing
        newline is not written.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        If you use the <code class="command">\o</code> command to redirect your
        query output you might wish to use <code class="command">\qecho</code>
        instead of this command.
        </p></div></dd><dt><span class="term"><code class="literal">\ef [<span class="optional"> <em class="replaceable"><code>function_description</code></em> [<span class="optional">  <em class="replaceable"><code>line_number</code></em> </span>] </span>] </code></span></dt><dd><p>
         This command fetches and edits the definition of the named function or procedure,
         in the form of a <code class="command">CREATE OR REPLACE FUNCTION</code> or
         <code class="command">CREATE OR REPLACE PROCEDURE</code> command.
         Editing is done in the same way as for <code class="literal">\edit</code>.
         After the editor exits, the updated command waits in the query buffer;
         type semicolon or <code class="literal">\g</code> to send it, or <code class="literal">\r</code>
         to cancel.
        </p><p>
         The target function can be specified by name alone, or by name
         and arguments, for example <code class="literal">foo(integer, text)</code>.
         The argument types must be given if there is more
         than one function of the same name.
        </p><p>
         If no function is specified, a blank <code class="command">CREATE FUNCTION</code>
         template is presented for editing.
        </p><p>
        If a line number is specified, <span class="application">psql</span> will
        position the cursor on the specified line of the function body.
        (Note that the function body typically does not begin on the first
        line of the file.)
        </p><p>
        Unlike most other meta-commands, the entire remainder of the line is
        always taken to be the argument(s) of <code class="command">\ef</code>, and neither
        variable interpolation nor backquote expansion are performed in the
        arguments.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        See under <a class="xref" href="app-psql.html#APP-PSQL-ENVIRONMENT" title="Environment">Environment</a> for how to configure and
        customize your editor.
        </p></div></dd><dt><span class="term"><code class="literal">\encoding [ <em class="replaceable"><code>encoding</code></em> ]</code></span></dt><dd><p>
        Sets the client character set encoding.  Without an argument, this command
        shows the current encoding.
        </p></dd><dt><span class="term"><code class="literal">\errverbose</code></span></dt><dd><p>
        Repeats the most recent server error message at maximum
        verbosity, as though <code class="varname">VERBOSITY</code> were set
        to <code class="literal">verbose</code> and <code class="varname">SHOW_CONTEXT</code> were
        set to <code class="literal">always</code>.
        </p></dd><dt><span class="term"><code class="literal">\ev [<span class="optional"> <em class="replaceable"><code>view_name</code></em> [<span class="optional">  <em class="replaceable"><code>line_number</code></em> </span>] </span>] </code></span></dt><dd><p>
         This command fetches and edits the definition of the named view,
         in the form of a <code class="command">CREATE OR REPLACE VIEW</code> command.
         Editing is done in the same way as for <code class="literal">\edit</code>.
         After the editor exits, the updated command waits in the query buffer;
         type semicolon or <code class="literal">\g</code> to send it, or <code class="literal">\r</code>
         to cancel.
        </p><p>
         If no view is specified, a blank <code class="command">CREATE VIEW</code>
         template is presented for editing.
        </p><p>
         If a line number is specified, <span class="application">psql</span> will
         position the cursor on the specified line of the view definition.
        </p><p>
        Unlike most other meta-commands, the entire remainder of the line is
        always taken to be the argument(s) of <code class="command">\ev</code>, and neither
        variable interpolation nor backquote expansion are performed in the
        arguments.
        </p></dd><dt><span class="term"><code class="literal">\f [ <em class="replaceable"><code>string</code></em> ]</code></span></dt><dd><p>
        Sets the field separator for unaligned query output. The default
        is the vertical bar (<code class="literal">|</code>). It is equivalent to
        <code class="command">\pset fieldsep</code>.
        </p></dd><dt><span class="term"><code class="literal">\g [ <em class="replaceable"><code>filename</code></em> ]</code><br /></span><span class="term"><code class="literal">\g [ |<em class="replaceable"><code>command</code></em> ]</code></span></dt><dd><p>
        Sends the current query buffer to the server for execution.
        If an argument is given, the query's output is written to the named
        file or piped to the given shell command, instead of displaying it as
        usual.  The file or command is written to only if the query
        successfully returns zero or more tuples, not if the query fails or
        is a non-data-returning SQL command.
        </p><p>
        If the current query buffer is empty, the most recently sent query is
        re-executed instead.  Except for that behavior, <code class="literal">\g</code>
        without an argument is essentially equivalent to a semicolon.
        A <code class="literal">\g</code> with argument is a <span class="quote">“<span class="quote">one-shot</span>”</span>
        alternative to the <code class="command">\o</code> command.
        </p><p>
        If the argument begins with <code class="literal">|</code>, then the entire remainder
        of the line is taken to be
        the <em class="replaceable"><code>command</code></em> to execute,
        and neither variable interpolation nor backquote expansion are
        performed in it.  The rest of the line is simply passed literally to
        the shell.
        </p></dd><dt><span class="term"><code class="literal">\gdesc</code></span></dt><dd><p>
         Shows the description (that is, the column names and data types)
         of the result of the current query buffer.  The query is not
         actually executed; however, if it contains some type of syntax
         error, that error will be reported in the normal way.
        </p><p>
         If the current query buffer is empty, the most recently sent query
         is described instead.
        </p></dd><dt><span class="term"><code class="literal">\gexec</code></span></dt><dd><p>
         Sends the current query buffer to the server, then treats
         each column of each row of the query's output (if any) as a SQL
         statement to be executed.  For example, to create an index on each
         column of <code class="structname">my_table</code>:
</p><pre class="programlisting">
=&gt; <strong class="userinput"><code>SELECT format('create index on my_table(%I)', attname)</code></strong>
-&gt; <strong class="userinput"><code>FROM pg_attribute</code></strong>
-&gt; <strong class="userinput"><code>WHERE attrelid = 'my_table'::regclass AND attnum &gt; 0</code></strong>
-&gt; <strong class="userinput"><code>ORDER BY attnum</code></strong>
-&gt; <strong class="userinput"><code>\gexec</code></strong>
CREATE INDEX
CREATE INDEX
CREATE INDEX
CREATE INDEX
</pre><p>
        </p><p>
         The generated queries are executed in the order in which the rows
         are returned, and left-to-right within each row if there is more
         than one column.  NULL fields are ignored.  The generated queries
         are sent literally to the server for processing, so they cannot be
         <span class="application">psql</span> meta-commands nor contain <span class="application">psql</span>
         variable references.  If any individual query fails, execution of
         the remaining queries continues
         unless <code class="varname">ON_ERROR_STOP</code> is set.  Execution of each
         query is subject to <code class="varname">ECHO</code> processing.
         (Setting <code class="varname">ECHO</code> to <code class="literal">all</code>
         or <code class="literal">queries</code> is often advisable when
         using <code class="command">\gexec</code>.)  Query logging, single-step mode,
         timing, and other query execution features apply to each generated
         query as well.
        </p><p>
         If the current query buffer is empty, the most recently sent query
         is re-executed instead.
        </p></dd><dt><span class="term"><code class="literal">\gset [ <em class="replaceable"><code>prefix</code></em> ]</code></span></dt><dd><p>
         Sends the current query buffer to the server and stores the
         query's output into <span class="application">psql</span> variables (see <a class="xref" href="app-psql.html#APP-PSQL-VARIABLES" title="Variables">Variables</a>).
         The query to be executed must return exactly one row.  Each column of
         the row is stored into a separate variable, named the same as the
         column.  For example:
</p><pre class="programlisting">
=&gt; <strong class="userinput"><code>SELECT 'hello' AS var1, 10 AS var2</code></strong>
-&gt; <strong class="userinput"><code>\gset</code></strong>
=&gt; <strong class="userinput"><code>\echo :var1 :var2</code></strong>
hello 10
</pre><p>
        </p><p>
         If you specify a <em class="replaceable"><code>prefix</code></em>,
         that string is prepended to the query's column names to create the
         variable names to use:
</p><pre class="programlisting">
=&gt; <strong class="userinput"><code>SELECT 'hello' AS var1, 10 AS var2</code></strong>
-&gt; <strong class="userinput"><code>\gset result_</code></strong>
=&gt; <strong class="userinput"><code>\echo :result_var1 :result_var2</code></strong>
hello 10
</pre><p>
        </p><p>
         If a column result is NULL, the corresponding variable is unset
         rather than being set.
        </p><p>
         If the query fails or does not return one row,
         no variables are changed.
        </p><p>
         If the current query buffer is empty, the most recently sent query
         is re-executed instead.
        </p></dd><dt><span class="term"><code class="literal">\gx [ <em class="replaceable"><code>filename</code></em> ]</code><br /></span><span class="term"><code class="literal">\gx [ |<em class="replaceable"><code>command</code></em> ]</code></span></dt><dd><p>
        <code class="literal">\gx</code> is equivalent to <code class="literal">\g</code>, but
        forces expanded output mode for this query.  See <code class="literal">\x</code>.
        </p></dd><dt><span class="term"><code class="literal">\h</code> or <code class="literal">\help</code> <code class="literal">[ <em class="replaceable"><code>command</code></em> ]</code></span></dt><dd><p>
        Gives syntax help on the specified <acronym class="acronym">SQL</acronym>
        command. If <em class="replaceable"><code>command</code></em>
        is not specified, then <span class="application">psql</span> will list
        all the commands for which syntax help is available. If
        <em class="replaceable"><code>command</code></em> is an
        asterisk (<code class="literal">*</code>), then syntax help on all
        <acronym class="acronym">SQL</acronym> commands is shown.
        </p><p>
        Unlike most other meta-commands, the entire remainder of the line is
        always taken to be the argument(s) of <code class="command">\help</code>, and neither
        variable interpolation nor backquote expansion are performed in the
        arguments.
        </p><div class="note"><h3 class="title">Note</h3><p>
        To simplify typing, commands that consists of several words do
        not have to be quoted. Thus it is fine to type <strong class="userinput"><code>\help
        alter table</code></strong>.
        </p></div></dd><dt><span class="term"><code class="literal">\H</code> or <code class="literal">\html</code></span></dt><dd><p>
        Turns on <acronym class="acronym">HTML</acronym> query output format. If the
        <acronym class="acronym">HTML</acronym> format is already on, it is switched
        back to the default aligned text format. This command is for
        compatibility and convenience, but see <code class="command">\pset</code>
        about setting other output options.
        </p></dd><dt><span class="term"><code class="literal">\i</code> or <code class="literal">\include</code> <em class="replaceable"><code>filename</code></em></span></dt><dd><p>
        Reads input from the file <em class="replaceable"><code>filename</code></em> and executes it as
        though it had been typed on the keyboard.
        </p><p>
        If <em class="replaceable"><code>filename</code></em> is <code class="literal">-</code>
        (hyphen), then standard input is read until an EOF indication
        or <code class="command">\q</code> meta-command.  This can be used to intersperse
        interactive input with input from files.  Note that Readline behavior
        will be used only if it is active at the outermost level.
        </p><div class="note"><h3 class="title">Note</h3><p>
        If you want to see the lines on the screen as they are read you
        must set the variable <code class="varname">ECHO</code> to
        <code class="literal">all</code>.
        </p></div></dd><dt id="PSQL-METACOMMAND-IF"><span class="term"><code class="literal">\if</code> <em class="replaceable"><code>expression</code></em><br /></span><span class="term"><code class="literal">\elif</code> <em class="replaceable"><code>expression</code></em><br /></span><span class="term"><code class="literal">\else</code><br /></span><span class="term"><code class="literal">\endif</code></span></dt><dd><p>
        This group of commands implements nestable conditional blocks.
        A conditional block must begin with an <code class="command">\if</code> and end
        with an <code class="command">\endif</code>.  In between there may be any number
        of <code class="command">\elif</code> clauses, which may optionally be followed
        by a single <code class="command">\else</code> clause.  Ordinary queries and
        other types of backslash commands may (and usually do) appear between
        the commands forming a conditional block.
        </p><p>
        The <code class="command">\if</code> and <code class="command">\elif</code> commands read
        their argument(s) and evaluate them as a boolean expression.  If the
        expression yields <code class="literal">true</code> then processing continues
        normally; otherwise, lines are skipped until a
        matching <code class="command">\elif</code>, <code class="command">\else</code>,
        or <code class="command">\endif</code> is reached.  Once
        an <code class="command">\if</code> or <code class="command">\elif</code> test has
        succeeded, the arguments of later <code class="command">\elif</code> commands in
        the same block are not evaluated but are treated as false.  Lines
        following an <code class="command">\else</code> are processed only if no earlier
        matching <code class="command">\if</code> or <code class="command">\elif</code> succeeded.
        </p><p>
        The <em class="replaceable"><code>expression</code></em> argument
        of an <code class="command">\if</code> or <code class="command">\elif</code> command
        is subject to variable interpolation and backquote expansion, just
        like any other backslash command argument.  After that it is evaluated
        like the value of an on/off option variable.  So a valid value
        is any unambiguous case-insensitive match for one of:
        <code class="literal">true</code>, <code class="literal">false</code>, <code class="literal">1</code>,
        <code class="literal">0</code>, <code class="literal">on</code>, <code class="literal">off</code>,
        <code class="literal">yes</code>, <code class="literal">no</code>.  For example,
        <code class="literal">t</code>, <code class="literal">T</code>, and <code class="literal">tR</code>
        will all be considered to be <code class="literal">true</code>.
        </p><p>
        Expressions that do not properly evaluate to true or false will
        generate a warning and be treated as false.
        </p><p>
        Lines being skipped are parsed normally to identify queries and
        backslash commands, but queries are not sent to the server, and
        backslash commands other than conditionals
        (<code class="command">\if</code>, <code class="command">\elif</code>,
        <code class="command">\else</code>, <code class="command">\endif</code>) are
        ignored.  Conditional commands are checked only for valid nesting.
        Variable references in skipped lines are not expanded, and backquote
        expansion is not performed either.
        </p><p>
        All the backslash commands of a given conditional block must appear in
        the same source file. If EOF is reached on the main input file or an
        <code class="command">\include</code>-ed file before all local
        <code class="command">\if</code>-blocks have been closed,
        then <span class="application">psql</span> will raise an error.
        </p><p>
         Here is an example:
        </p><pre class="programlisting">
-- check for the existence of two separate records in the database and store
-- the results in separate psql variables
SELECT
    EXISTS(SELECT 1 FROM customer WHERE customer_id = 123) as is_customer,
    EXISTS(SELECT 1 FROM employee WHERE employee_id = 456) as is_employee
\gset
\if :is_customer
    SELECT * FROM customer WHERE customer_id = 123;
\elif :is_employee
    \echo 'is not a customer but is an employee'
    SELECT * FROM employee WHERE employee_id = 456;
\else
    \if yes
        \echo 'not a customer or employee'
    \else
        \echo 'this will never print'
    \endif
\endif
</pre></dd><dt><span class="term"><code class="literal">\ir</code> or <code class="literal">\include_relative</code> <em class="replaceable"><code>filename</code></em></span></dt><dd><p>
        The <code class="literal">\ir</code> command is similar to <code class="literal">\i</code>, but resolves
        relative file names differently.  When executing in interactive mode,
        the two commands behave identically.  However, when invoked from a
        script, <code class="literal">\ir</code> interprets file names relative to the
        directory in which the script is located, rather than the current
        working directory.
        </p></dd><dt><span class="term"><code class="literal">\l[+]</code> or <code class="literal">\list[+] [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        List the databases in the server and show their names, owners,
        character set encodings, and access privileges.
        If <em class="replaceable"><code>pattern</code></em> is specified,
        only databases whose names match the pattern are listed.
        If <code class="literal">+</code> is appended to the command name, database
        sizes, default tablespaces, and descriptions are also displayed.
        (Size information is only available for databases that the current
        user can connect to.)
        </p></dd><dt><span class="term"><code class="literal">\lo_export <em class="replaceable"><code>loid</code></em> <em class="replaceable"><code>filename</code></em></code></span></dt><dd><p>
        Reads the large object with <acronym class="acronym">OID</acronym> <em class="replaceable"><code>loid</code></em> from the database and
        writes it to <em class="replaceable"><code>filename</code></em>. Note that this is
        subtly different from the server function
        <code class="function">lo_export</code>, which acts with the permissions
        of the user that the database server runs as and on the server's
        file system.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        Use <code class="command">\lo_list</code> to find out the large object's
        <acronym class="acronym">OID</acronym>.
        </p></div></dd><dt><span class="term"><code class="literal">\lo_import <em class="replaceable"><code>filename</code></em> [ <em class="replaceable"><code>comment</code></em> ]</code></span></dt><dd><p>
        Stores the file into a <span class="productname">PostgreSQL</span>
        large object. Optionally, it associates the given
        comment with the object. Example:
</p><pre class="programlisting">
foo=&gt; <strong class="userinput"><code>\lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'</code></strong>
lo_import 152801
</pre><p>
        The response indicates that the large object received object
        ID 152801, which can be used to access the newly-created large
        object in the future. For the sake of readability, it is
        recommended to always associate a human-readable comment with
        every object. Both OIDs and comments can be viewed with the
        <code class="command">\lo_list</code> command.
        </p><p>
        Note that this command is subtly different from the server-side
        <code class="function">lo_import</code> because it acts as the local user
        on the local file system, rather than the server's user and file
        system.
        </p></dd><dt><span class="term"><code class="literal">\lo_list</code></span></dt><dd><p>
        Shows a list of all <span class="productname">PostgreSQL</span>
        large objects currently stored in the database,
        along with any comments provided for them.
        </p></dd><dt><span class="term"><code class="literal">\lo_unlink <em class="replaceable"><code>loid</code></em></code></span></dt><dd><p>
        Deletes the large object with <acronym class="acronym">OID</acronym>
        <em class="replaceable"><code>loid</code></em> from the
        database.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        Use <code class="command">\lo_list</code> to find out the large object's
        <acronym class="acronym">OID</acronym>.
        </p></div></dd><dt><span class="term"><code class="literal">\o</code> or <code class="literal">\out [ <em class="replaceable"><code>filename</code></em> ]</code><br /></span><span class="term"><code class="literal">\o</code> or <code class="literal">\out [ |<em class="replaceable"><code>command</code></em> ]</code></span></dt><dd><p>
        Arranges to save future query results to the file <em class="replaceable"><code>filename</code></em> or pipe future results
        to the shell command <em class="replaceable"><code>command</code></em>. If no argument is
        specified, the query output is reset to the standard output.
        </p><p>
        If the argument begins with <code class="literal">|</code>, then the entire remainder
        of the line is taken to be
        the <em class="replaceable"><code>command</code></em> to execute,
        and neither variable interpolation nor backquote expansion are
        performed in it.  The rest of the line is simply passed literally to
        the shell.
        </p><p>
        <span class="quote">“<span class="quote">Query results</span>”</span> includes all tables, command
        responses, and notices obtained from the database server, as
        well as output of various backslash commands that query the
        database (such as <code class="command">\d</code>); but not error
        messages.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        To intersperse text output in between query results, use
        <code class="command">\qecho</code>.
        </p></div></dd><dt><span class="term"><code class="literal">\p</code> or <code class="literal">\print</code></span></dt><dd><p>
        Print the current query buffer to the standard output.
        If the current query buffer is empty, the most recently executed query
        is printed instead.
        </p></dd><dt><span class="term"><code class="literal">\password [ <em class="replaceable"><code>username</code></em> ]</code></span></dt><dd><p>
        Changes the password of the specified user (by default, the current
        user).  This command prompts for the new password, encrypts it, and
        sends it to the server as an <code class="command">ALTER ROLE</code> command.  This
        makes sure that the new password does not appear in cleartext in the
        command history, the server log, or elsewhere.
        </p></dd><dt><span class="term"><code class="literal">\prompt [ <em class="replaceable"><code>text</code></em> ] <em class="replaceable"><code>name</code></em></code></span></dt><dd><p>
         Prompts the user to supply text, which is assigned to the variable
         <em class="replaceable"><code>name</code></em>.
         An optional prompt string, <em class="replaceable"><code>text</code></em>, can be specified.  (For multiword
         prompts, surround the text with single quotes.)
        </p><p>
         By default, <code class="literal">\prompt</code> uses the terminal for input and
         output.  However, if the <code class="option">-f</code> command line switch was
         used, <code class="literal">\prompt</code> uses standard input and standard output.
        </p></dd><dt><span class="term"><code class="literal">\pset [ <em class="replaceable"><code>option</code></em> [ <em class="replaceable"><code>value</code></em> ] ]</code></span></dt><dd><p>
        This command sets options affecting the output of query result tables.
        <em class="replaceable"><code>option</code></em>
        indicates which option is to be set. The semantics of
        <em class="replaceable"><code>value</code></em> vary depending
        on the selected option.  For some options, omitting <em class="replaceable"><code>value</code></em> causes the option to be toggled
        or unset, as described under the particular option.  If no such
        behavior is mentioned, then omitting
        <em class="replaceable"><code>value</code></em> just results in
        the current setting being displayed.
        </p><p>
        <code class="command">\pset</code> without any arguments displays the current status
        of all printing options.
        </p><p>
        Adjustable printing options are:
        </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">border</code></span></dt><dd><p>
          The <em class="replaceable"><code>value</code></em> must be a
          number. In general, the higher
          the number the more borders and lines the tables will have,
          but details depend on the particular format.
          In <acronym class="acronym">HTML</acronym> format, this will translate directly
          into the <code class="literal">border=...</code> attribute.
          In most other formats only values 0 (no border), 1 (internal
          dividing lines), and 2 (table frame) make sense, and values above 2
          will be treated the same as <code class="literal">border = 2</code>.
          The <code class="literal">latex</code> and <code class="literal">latex-longtable</code>
          formats additionally allow a value of 3 to add dividing lines
          between data rows.
          </p></dd><dt><span class="term"><code class="literal">columns</code></span></dt><dd><p>
          Sets the target width for the <code class="literal">wrapped</code> format, and also
          the width limit for determining whether output is wide enough to
          require the pager or switch to the vertical display in expanded auto
          mode.
          Zero (the default) causes the target width to be controlled by the
          environment variable <code class="envar">COLUMNS</code>, or the detected screen width
          if <code class="envar">COLUMNS</code> is not set.
          In addition, if <code class="literal">columns</code> is zero then the
          <code class="literal">wrapped</code> format only affects screen output.
          If <code class="literal">columns</code> is nonzero then file and pipe output is
          wrapped to that width as well.
          </p></dd><dt><span class="term"><code class="literal">csv_fieldsep</code></span></dt><dd><p>
          Specifies the field separator to be used in
          <acronym class="acronym">CSV</acronym> output format.  If the separator character
          appears in a field's value, that field is output within double
          quotes, following standard <acronym class="acronym">CSV</acronym> rules.
          The default is a comma.
          </p></dd><dt><span class="term"><code class="literal">expanded</code> (or <code class="literal">x</code>)</span></dt><dd><p>
          If <em class="replaceable"><code>value</code></em> is specified it
          must be either <code class="literal">on</code> or <code class="literal">off</code>, which
          will enable or disable expanded mode, or <code class="literal">auto</code>.
          If <em class="replaceable"><code>value</code></em> is omitted the
          command toggles between the on and off settings.  When expanded mode
          is enabled, query results are displayed in two columns, with the
          column name on the left and the data on the right. This mode is
          useful if the data wouldn't fit on the screen in the
          normal <span class="quote">“<span class="quote">horizontal</span>”</span> mode.  In the auto setting, the
          expanded mode is used whenever the query output has more than one
          column and is wider than the screen; otherwise, the regular mode is
          used.  The auto setting is only
          effective in the aligned and wrapped formats.  In other formats, it
          always behaves as if the expanded mode is off.
          </p></dd><dt><span class="term"><code class="literal">fieldsep</code></span></dt><dd><p>
          Specifies the field separator to be used in unaligned output
          format. That way one can create, for example, tab-separated
          output, which other programs might prefer. To
          set a tab as field separator, type <code class="literal">\pset fieldsep
          '\t'</code>. The default field separator is
          <code class="literal">'|'</code> (a vertical bar).
          </p></dd><dt><span class="term"><code class="literal">fieldsep_zero</code></span></dt><dd><p>
          Sets the field separator to use in unaligned output format to a zero
          byte.
          </p></dd><dt><span class="term"><code class="literal">footer</code></span></dt><dd><p>
          If <em class="replaceable"><code>value</code></em> is specified
          it must be either <code class="literal">on</code> or <code class="literal">off</code>
          which will enable or disable display of the table footer
          (the <code class="literal">(<em class="replaceable"><code>n</code></em> rows)</code> count).
          If <em class="replaceable"><code>value</code></em> is omitted the
          command toggles footer display on or off.
          </p></dd><dt><span class="term"><code class="literal">format</code></span></dt><dd><p>
          Sets the output format to one of <code class="literal">aligned</code>,
          <code class="literal">asciidoc</code>,
          <code class="literal">csv</code>,
          <code class="literal">html</code>,
          <code class="literal">latex</code>,
          <code class="literal">latex-longtable</code>, <code class="literal">troff-ms</code>,
          <code class="literal">unaligned</code>, or <code class="literal">wrapped</code>.
          Unique abbreviations are allowed.
          </p><p><code class="literal">aligned</code> format is the standard,
          human-readable, nicely formatted text output; this is the default.
          </p><p><code class="literal">unaligned</code> format writes all columns of a row on one
          line, separated by the currently active field separator. This
          is useful for creating output that might be intended to be read
          in by other programs, for example, tab-separated or comma-separated
          format.  However, the field separator character is not treated
          specially if it appears in a column's value;
          so <acronym class="acronym">CSV</acronym> format may be better suited for such
          purposes.
          </p><p><code class="literal">csv</code> format
          <a id="id-1.9.4.18.8.4.10.1.69.2.3.1.8.2.4.2" class="indexterm"></a>
          writes column values separated by commas, applying the quoting
          rules described in
          <a class="ulink" href="https://tools.ietf.org/html/rfc4180" target="_top">RFC 4180</a>.
          This output is compatible with the CSV format of the server's
          <code class="command">COPY</code> command.
          A header line with column names is generated unless
          the <code class="literal">tuples_only</code> parameter is
          <code class="literal">on</code>. Titles and footers are not printed.
          Each row is terminated by the system-dependent end-of-line character,
          which is typically a single newline (<code class="literal">\n</code>) for
          Unix-like systems or a carriage return and newline sequence
          (<code class="literal">\r\n</code>) for Microsoft Windows.
          Field separator characters other than comma can be selected with
          <code class="command">\pset csv_fieldsep</code>.
          </p><p><code class="literal">wrapped</code> format is like <code class="literal">aligned</code> but wraps
          wide data values across lines to make the output fit in the target
          column width.  The target width is determined as described under
          the <code class="literal">columns</code> option.  Note that <span class="application">psql</span> will
          not attempt to wrap column header titles; therefore,
          <code class="literal">wrapped</code> format behaves the same as <code class="literal">aligned</code>
          if the total width needed for column headers exceeds the target.
          </p><p>
          The <code class="literal">asciidoc</code>, <code class="literal">html</code>,
          <code class="literal">latex</code>, <code class="literal">latex-longtable</code>, and
          <code class="literal">troff-ms</code> formats put out tables that are intended
          to be included in documents using the respective mark-up
          language. They are not complete documents! This might not be
          necessary in <acronym class="acronym">HTML</acronym>, but in
          <span class="application">LaTeX</span> you must have a complete
          document wrapper.
          The <code class="literal">latex</code> format
          uses <span class="application">LaTeX</span>'s <code class="literal">tabular</code>
          environment.
          The <code class="literal">latex-longtable</code> format
          requires the <span class="application">LaTeX</span>
          <code class="literal">longtable</code> and <code class="literal">booktabs</code> packages.
          </p></dd><dt><span class="term"><code class="literal">linestyle</code></span></dt><dd><p>
          Sets the border line drawing style to one
          of <code class="literal">ascii</code>, <code class="literal">old-ascii</code>,
          or <code class="literal">unicode</code>.
          Unique abbreviations are allowed.  (That would mean one
          letter is enough.)
          The default setting is <code class="literal">ascii</code>.
          This option only affects the <code class="literal">aligned</code> and
          <code class="literal">wrapped</code> output formats.
          </p><p><code class="literal">ascii</code> style uses plain <acronym class="acronym">ASCII</acronym>
          characters.  Newlines in data are shown using
          a <code class="literal">+</code> symbol in the right-hand margin.
          When the <code class="literal">wrapped</code> format wraps data from
          one line to the next without a newline character, a dot
          (<code class="literal">.</code>) is shown in the right-hand margin of the first line,
          and again in the left-hand margin of the following line.
          </p><p><code class="literal">old-ascii</code> style uses plain <acronym class="acronym">ASCII</acronym>
          characters, using the formatting style used
          in <span class="productname">PostgreSQL</span> 8.4 and earlier.
          Newlines in data are shown using a <code class="literal">:</code>
          symbol in place of the left-hand column separator.
          When the data is wrapped from one line
          to the next without a newline character, a <code class="literal">;</code>
          symbol is used in place of the left-hand column separator.
          </p><p><code class="literal">unicode</code> style uses Unicode box-drawing characters.
          Newlines in data are shown using a carriage return symbol
          in the right-hand margin.  When the data is wrapped from one line
          to the next without a newline character, an ellipsis symbol
          is shown in the right-hand margin of the first line, and
          again in the left-hand margin of the following line.
          </p><p>
          When the <code class="literal">border</code> setting is greater than zero,
          the <code class="literal">linestyle</code> option also determines the
          characters with which the border lines are drawn.
          Plain <acronym class="acronym">ASCII</acronym> characters work everywhere, but
          Unicode characters look nicer on displays that recognize them.
          </p></dd><dt><span class="term"><code class="literal">null</code></span></dt><dd><p>
          Sets the string to be printed in place of a null value.
          The default is to print nothing, which can easily be mistaken for
          an empty string. For example, one might prefer <code class="literal">\pset null
          '(null)'</code>.
          </p></dd><dt><span class="term"><code class="literal">numericlocale</code></span></dt><dd><p>
          If <em class="replaceable"><code>value</code></em> is specified
          it must be either <code class="literal">on</code> or <code class="literal">off</code>
          which will enable or disable display of a locale-specific character
          to separate groups of digits to the left of the decimal marker.
          If <em class="replaceable"><code>value</code></em> is omitted the
          command toggles between regular and locale-specific numeric output.
          </p></dd><dt><span class="term"><code class="literal">pager</code></span></dt><dd><p>
          Controls use of a pager program for query and <span class="application">psql</span>
          help output.  If the environment variable <code class="envar">PSQL_PAGER</code>
          or <code class="envar">PAGER</code> is set, the output is piped to the
          specified program.  Otherwise a platform-dependent default program
          (such as <code class="filename">more</code>) is used.
          </p><p>
          When the <code class="literal">pager</code> option is <code class="literal">off</code>, the pager
          program is not used. When the <code class="literal">pager</code> option is
          <code class="literal">on</code>, the pager is used when appropriate, i.e., when the
          output is to a terminal and will not fit on the screen.
          The <code class="literal">pager</code> option can also be set to <code class="literal">always</code>,
          which causes the pager to be used for all terminal output regardless
          of whether it fits on the screen.  <code class="literal">\pset pager</code>
          without a <em class="replaceable"><code>value</code></em>
          toggles pager use on and off.
          </p></dd><dt><span class="term"><code class="literal">pager_min_lines</code></span></dt><dd><p>
          If <code class="literal">pager_min_lines</code> is set to a number greater than the
          page height, the pager program will not be called unless there are
          at least this many lines of output to show. The default setting
          is 0.
          </p></dd><dt><span class="term"><code class="literal">recordsep</code></span></dt><dd><p>
          Specifies the record (line) separator to use in unaligned
          output format. The default is a newline character.
          </p></dd><dt><span class="term"><code class="literal">recordsep_zero</code></span></dt><dd><p>
          Sets the record separator to use in unaligned output format to a zero
          byte.
          </p></dd><dt><span class="term"><code class="literal">tableattr</code> (or <code class="literal">T</code>)</span></dt><dd><p>
          In <acronym class="acronym">HTML</acronym> format, this specifies attributes
          to be placed inside the <code class="sgmltag-element">table</code> tag.  This
          could for example be <code class="literal">cellpadding</code> or
          <code class="literal">bgcolor</code>. Note that you probably don't want
          to specify <code class="literal">border</code> here, as that is already
          taken care of by <code class="literal">\pset border</code>.
          If no
          <em class="replaceable"><code>value</code></em> is given,
          the table attributes are unset.
          </p><p>
          In <code class="literal">latex-longtable</code> format, this controls
          the proportional width of each column containing a left-aligned
          data type.  It is specified as a whitespace-separated list of values,
          e.g. <code class="literal">'0.2 0.2 0.6'</code>.  Unspecified output columns
          use the last specified value.
          </p></dd><dt><span class="term"><code class="literal">title</code> (or <code class="literal">C</code>)</span></dt><dd><p>
          Sets the table title for any subsequently printed tables. This
          can be used to give your output descriptive tags. If no
          <em class="replaceable"><code>value</code></em> is given,
          the title is unset.
          </p></dd><dt><span class="term"><code class="literal">tuples_only</code> (or <code class="literal">t</code>)</span></dt><dd><p>
          If <em class="replaceable"><code>value</code></em> is specified
          it must be either <code class="literal">on</code> or <code class="literal">off</code>
          which will enable or disable tuples-only mode.
          If <em class="replaceable"><code>value</code></em> is omitted the
          command toggles between regular and tuples-only output.
          Regular output includes extra information such
          as column headers, titles, and various footers. In tuples-only
          mode, only actual table data is shown.
          </p></dd><dt><span class="term"><code class="literal">unicode_border_linestyle</code></span></dt><dd><p>
          Sets the border drawing style for the <code class="literal">unicode</code>
          line style to one of <code class="literal">single</code>
          or <code class="literal">double</code>.
          </p></dd><dt><span class="term"><code class="literal">unicode_column_linestyle</code></span></dt><dd><p>
          Sets the column drawing style for the <code class="literal">unicode</code>
          line style to one of <code class="literal">single</code>
          or <code class="literal">double</code>.
          </p></dd><dt><span class="term"><code class="literal">unicode_header_linestyle</code></span></dt><dd><p>
          Sets the header drawing style for the <code class="literal">unicode</code>
          line style to one of <code class="literal">single</code>
          or <code class="literal">double</code>.
          </p></dd></dl></div><p>
        </p><p>
        Illustrations of how these different formats look can be seen in
        the <a class="xref" href="app-psql.html#APP-PSQL-EXAMPLES" title="Examples">Examples</a> section.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        There are various shortcut commands for <code class="command">\pset</code>. See
        <code class="command">\a</code>, <code class="command">\C</code>, <code class="command">\f</code>,
        <code class="command">\H</code>, <code class="command">\t</code>, <code class="command">\T</code>,
        and <code class="command">\x</code>.
        </p></div></dd><dt><span class="term"><code class="literal">\q</code> or <code class="literal">\quit</code></span></dt><dd><p>
        Quits the <span class="application">psql</span> program.
        In a script file, only execution of that script is terminated.
        </p></dd><dt><span class="term"><code class="literal">\qecho <em class="replaceable"><code>text</code></em> [ ... ] </code></span></dt><dd><p>
        This command is identical to <code class="command">\echo</code> except
        that the output will be written to the query output channel, as
        set by <code class="command">\o</code>.
        </p></dd><dt><span class="term"><code class="literal">\r</code> or <code class="literal">\reset</code></span></dt><dd><p>
        Resets (clears) the query buffer.
        </p></dd><dt><span class="term"><code class="literal">\s [ <em class="replaceable"><code>filename</code></em> ]</code></span></dt><dd><p>
        Print <span class="application">psql</span>'s command line history
        to <em class="replaceable"><code>filename</code></em>.
        If <em class="replaceable"><code>filename</code></em> is omitted,
        the history is written to the standard output (using the pager if
        appropriate).  This command is not available
        if <span class="application">psql</span> was built
        without <span class="application">Readline</span> support.
        </p></dd><dt><span class="term"><code class="literal">\set [ <em class="replaceable"><code>name</code></em> [ <em class="replaceable"><code>value</code></em> [ ... ] ] ]</code></span></dt><dd><p>
        Sets the <span class="application">psql</span> variable <em class="replaceable"><code>name</code></em> to <em class="replaceable"><code>value</code></em>, or if more than one value
        is given, to the concatenation of all of them. If only one
        argument is given, the variable is set to an empty-string value. To
        unset a variable, use the <code class="command">\unset</code> command.
        </p><p><code class="command">\set</code> without any arguments displays the names and values
        of all currently-set <span class="application">psql</span> variables.
        </p><p>
        Valid variable names can contain letters, digits, and
        underscores. See the section <a class="xref" href="app-psql.html#APP-PSQL-VARIABLES" title="Variables">Variables</a> below for details.
        Variable names are case-sensitive.
        </p><p>
        Certain variables are special, in that they
        control <span class="application">psql</span>'s behavior or are
        automatically set to reflect connection state.  These variables are
        documented in <a class="xref" href="app-psql.html#APP-PSQL-VARIABLES" title="Variables">Variables</a>, below.
        </p><div class="note"><h3 class="title">Note</h3><p>
        This command is unrelated to the <acronym class="acronym">SQL</acronym>
        command <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a>.
        </p></div></dd><dt><span class="term"><code class="literal">\setenv <em class="replaceable"><code>name</code></em> [ <em class="replaceable"><code>value</code></em> ]</code></span></dt><dd><p>
        Sets the environment variable <em class="replaceable"><code>name</code></em> to <em class="replaceable"><code>value</code></em>, or if the
        <em class="replaceable"><code>value</code></em> is
        not supplied, unsets the environment variable. Example:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\setenv PAGER less</code></strong>
testdb=&gt; <strong class="userinput"><code>\setenv LESS -imx4F</code></strong>
</pre></dd><dt><span class="term"><code class="literal">\sf[+] <em class="replaceable"><code>function_description</code></em> </code></span></dt><dd><p>
         This command fetches and shows the definition of the named function or procedure,
         in the form of a <code class="command">CREATE OR REPLACE FUNCTION</code> or
         <code class="command">CREATE OR REPLACE PROCEDURE</code> command.
         The definition is printed to the current query output channel,
         as set by <code class="command">\o</code>.
        </p><p>
         The target function can be specified by name alone, or by name
         and arguments, for example <code class="literal">foo(integer, text)</code>.
         The argument types must be given if there is more
         than one function of the same name.
        </p><p>
         If <code class="literal">+</code> is appended to the command name, then the
         output lines are numbered, with the first line of the function body
         being line 1.
        </p><p>
        Unlike most other meta-commands, the entire remainder of the line is
        always taken to be the argument(s) of <code class="command">\sf</code>, and neither
        variable interpolation nor backquote expansion are performed in the
        arguments.
        </p></dd><dt><span class="term"><code class="literal">\sv[+] <em class="replaceable"><code>view_name</code></em> </code></span></dt><dd><p>
          This command fetches and shows the definition of the named view,
          in the form of a <code class="command">CREATE OR REPLACE VIEW</code> command.
          The definition is printed to the current query output channel,
          as set by <code class="command">\o</code>.
         </p><p>
          If <code class="literal">+</code> is appended to the command name, then the
          output lines are numbered from 1.
         </p><p>
        Unlike most other meta-commands, the entire remainder of the line is
        always taken to be the argument(s) of <code class="command">\sv</code>, and neither
        variable interpolation nor backquote expansion are performed in the
        arguments.
        </p></dd><dt><span class="term"><code class="literal">\t</code></span></dt><dd><p>
        Toggles the display of output column name headings and row count
        footer. This command is equivalent to <code class="literal">\pset
        tuples_only</code> and is provided for convenience.
        </p></dd><dt><span class="term"><code class="literal">\T <em class="replaceable"><code>table_options</code></em></code></span></dt><dd><p>
        Specifies attributes to be placed within the
        <code class="sgmltag-element">table</code> tag in <acronym class="acronym">HTML</acronym>
        output format. This command is equivalent to <code class="literal">\pset
        tableattr <em class="replaceable"><code>table_options</code></em></code>.
        </p></dd><dt><span class="term"><code class="literal">\timing [ <em class="replaceable"><code>on</code></em> | <em class="replaceable"><code>off</code></em> ]</code></span></dt><dd><p>
         With a parameter, turns displaying of how long each SQL statement
         takes on or off.  Without a parameter, toggles the display between
         on and off.  The display is in milliseconds; intervals longer than
         1 second are also shown in minutes:seconds format, with hours and
         days fields added if needed.
        </p></dd><dt><span class="term"><code class="literal">\unset <em class="replaceable"><code>name</code></em></code></span></dt><dd><p>
        Unsets (deletes) the <span class="application">psql</span> variable <em class="replaceable"><code>name</code></em>.
        </p><p>
        Most variables that control <span class="application">psql</span>'s behavior
        cannot be unset; instead, an <code class="literal">\unset</code> command is interpreted
        as setting them to their default values.
        See <a class="xref" href="app-psql.html#APP-PSQL-VARIABLES" title="Variables">Variables</a>, below.
        </p></dd><dt><span class="term"><code class="literal">\w</code> or <code class="literal">\write</code> <em class="replaceable"><code>filename</code></em><br /></span><span class="term"><code class="literal">\w</code> or <code class="literal">\write</code> <code class="literal">|</code><em class="replaceable"><code>command</code></em></span></dt><dd><p>
        Writes the current query buffer to the file <em class="replaceable"><code>filename</code></em> or pipes it to the shell
        command <em class="replaceable"><code>command</code></em>.
        If the current query buffer is empty, the most recently executed query
        is written instead.
        </p><p>
        If the argument begins with <code class="literal">|</code>, then the entire remainder
        of the line is taken to be
        the <em class="replaceable"><code>command</code></em> to execute,
        and neither variable interpolation nor backquote expansion are
        performed in it.  The rest of the line is simply passed literally to
        the shell.
        </p></dd><dt><span class="term"><code class="literal">\watch [ <em class="replaceable"><code>seconds</code></em> ]</code></span></dt><dd><p>
        Repeatedly execute the current query buffer (as <code class="literal">\g</code> does)
        until interrupted or the query fails.  Wait the specified number of
        seconds (default 2) between executions.  Each query result is
        displayed with a header that includes the <code class="literal">\pset title</code>
        string (if any), the time as of query start, and the delay interval.
        </p><p>
        If the current query buffer is empty, the most recently sent query
        is re-executed instead.
        </p></dd><dt><span class="term"><code class="literal">\x [ <em class="replaceable"><code>on</code></em> | <em class="replaceable"><code>off</code></em> | <em class="replaceable"><code>auto</code></em> ]</code></span></dt><dd><p>
        Sets or toggles expanded table formatting mode. As such it is equivalent to
        <code class="literal">\pset expanded</code>.
       </p></dd><dt><span class="term"><code class="literal">\z [ <a class="link" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns"><em class="replaceable"><code>pattern</code></em></a> ]</code></span></dt><dd><p>
        Lists tables, views and sequences with their
        associated access privileges.
        If a <em class="replaceable"><code>pattern</code></em> is
        specified, only tables, views and sequences whose names match the
        pattern are listed.
        </p><p>
        This is an alias for <code class="command">\dp</code> (<span class="quote">“<span class="quote">display
        privileges</span>”</span>).
        </p></dd><dt><span class="term"><code class="literal">\! [ <em class="replaceable"><code>command</code></em> ]</code></span></dt><dd><p>
        With no argument, escapes to a sub-shell; <span class="application">psql</span>
        resumes when the sub-shell exits.  With an argument, executes the
        shell command <em class="replaceable"><code>command</code></em>.
        </p><p>
        Unlike most other meta-commands, the entire remainder of the line is
        always taken to be the argument(s) of <code class="command">\!</code>, and neither
        variable interpolation nor backquote expansion are performed in the
        arguments.  The rest of the line is simply passed literally to the
        shell.
        </p></dd><dt><span class="term"><code class="literal">\? [ <em class="replaceable"><code>topic</code></em> ]</code></span></dt><dd><p>
        Shows help information. The optional
        <em class="replaceable"><code>topic</code></em> parameter
        (defaulting to <code class="literal">commands</code>) selects which part of <span class="application">psql</span> is
        explained: <code class="literal">commands</code> describes <span class="application">psql</span>'s
        backslash commands; <code class="literal">options</code> describes the command-line
        options that can be passed to <span class="application">psql</span>;
        and <code class="literal">variables</code> shows help about <span class="application">psql</span> configuration
        variables.
        </p></dd><dt><span class="term"><code class="literal">\;</code></span></dt><dd><p>
        Backslash-semicolon is not a meta-command in the same way as the
        preceding commands; rather, it simply causes a semicolon to be
        added to the query buffer without any further processing.
        </p><p>
        Normally, <span class="application">psql</span> will dispatch a SQL command to the
        server as soon as it reaches the command-ending semicolon, even if
        more input remains on the current line.  Thus for example entering
</p><pre class="programlisting">
select 1; select 2; select 3;
</pre><p>
        will result in the three SQL commands being individually sent to
        the server, with each one's results being displayed before
        continuing to the next command.  However, a semicolon entered
        as <code class="literal">\;</code> will not trigger command processing, so that the
        command before it and the one after are effectively combined and
        sent to the server in one request.  So for example
</p><pre class="programlisting">
select 1\; select 2\; select 3;
</pre><p>
        results in sending the three SQL commands to the server in a single
        request, when the non-backslashed semicolon is reached.
        The server executes such a request as a single transaction,
        unless there are explicit <code class="command">BEGIN</code>/<code class="command">COMMIT</code>
        commands included in the string to divide it into multiple
        transactions.  (See <a class="xref" href="protocol-flow.html#PROTOCOL-FLOW-MULTI-STATEMENT" title="52.2.2.1. Multiple Statements in a Simple Query">Section 52.2.2.1</a>
        for more details about how the server handles multi-query strings.)
        <span class="application">psql</span> prints only the last query result
        it receives for each request; in this example, although all
        three <code class="command">SELECT</code>s are indeed executed, <span class="application">psql</span>
        only prints the <code class="literal">3</code>.
        </p></dd></dl></div><p>
  </p><div class="refsect3" id="APP-PSQL-PATTERNS"><h4>Patterns</h4><a id="id-1.9.4.18.8.4.11.2" class="indexterm"></a><p>
   The various <code class="literal">\d</code> commands accept a <em class="replaceable"><code>pattern</code></em> parameter to specify the
   object name(s) to be displayed.  In the simplest case, a pattern
   is just the exact name of the object.  The characters within a
   pattern are normally folded to lower case, just as in SQL names;
   for example, <code class="literal">\dt FOO</code> will display the table named
   <code class="literal">foo</code>.  As in SQL names, placing double quotes around
   a pattern stops folding to lower case.  Should you need to include
   an actual double quote character in a pattern, write it as a pair
   of double quotes within a double-quote sequence; again this is in
   accord with the rules for SQL quoted identifiers.  For example,
   <code class="literal">\dt "FOO""BAR"</code> will display the table named
   <code class="literal">FOO"BAR</code> (not <code class="literal">foo"bar</code>).  Unlike the normal
   rules for SQL names, you can put double quotes around just part
   of a pattern, for instance <code class="literal">\dt FOO"FOO"BAR</code> will display
   the table named <code class="literal">fooFOObar</code>.
  </p><p>
   Whenever the <em class="replaceable"><code>pattern</code></em> parameter
   is omitted completely, the <code class="literal">\d</code> commands display all objects
   that are visible in the current schema search path — this is
   equivalent to using <code class="literal">*</code> as the pattern.
   (An object is said to be <em class="firstterm">visible</em> if its
   containing schema is in the search path and no object of the same
   kind and name appears earlier in the search path. This is equivalent to the
   statement that the object can be referenced by name without explicit
   schema qualification.)
   To see all objects in the database regardless of visibility,
   use <code class="literal">*.*</code> as the pattern.
  </p><p>
   Within a pattern, <code class="literal">*</code> matches any sequence of characters
   (including no characters) and <code class="literal">?</code> matches any single character.
   (This notation is comparable to Unix shell file name patterns.)
   For example, <code class="literal">\dt int*</code> displays tables whose names
   begin with <code class="literal">int</code>.  But within double quotes, <code class="literal">*</code>
   and <code class="literal">?</code> lose these special meanings and are just matched
   literally.
  </p><p>
   A pattern that contains a dot (<code class="literal">.</code>) is interpreted as a schema
   name pattern followed by an object name pattern.  For example,
   <code class="literal">\dt foo*.*bar*</code> displays all tables whose table name
   includes <code class="literal">bar</code> that are in schemas whose schema name
   starts with <code class="literal">foo</code>.  When no dot appears, then the pattern
   matches only objects that are visible in the current schema search path.
   Again, a dot within double quotes loses its special meaning and is matched
   literally.
  </p><p>
   Advanced users can use regular-expression notations such as character
   classes, for example <code class="literal">[0-9]</code> to match any digit.  All regular
   expression special characters work as specified in
   <a class="xref" href="functions-matching.html#FUNCTIONS-POSIX-REGEXP" title="9.7.3. POSIX Regular Expressions">Section 9.7.3</a>, except for <code class="literal">.</code> which
   is taken as a separator as mentioned above, <code class="literal">*</code> which is
   translated to the regular-expression notation <code class="literal">.*</code>,
   <code class="literal">?</code> which is translated to <code class="literal">.</code>, and
   <code class="literal">$</code> which is matched literally.  You can emulate
   these pattern characters at need by writing
   <code class="literal">?</code> for <code class="literal">.</code>,
   <code class="literal">(<em class="replaceable"><code>R</code></em>+|)</code> for
   <code class="literal"><em class="replaceable"><code>R</code></em>*</code>, or
   <code class="literal">(<em class="replaceable"><code>R</code></em>|)</code> for
   <code class="literal"><em class="replaceable"><code>R</code></em>?</code>.
   <code class="literal">$</code> is not needed as a regular-expression character since
   the pattern must match the whole name, unlike the usual
   interpretation of regular expressions (in other words, <code class="literal">$</code>
   is automatically appended to your pattern).  Write <code class="literal">*</code> at the
   beginning and/or end if you don't wish the pattern to be anchored.
   Note that within double quotes, all regular expression special characters
   lose their special meanings and are matched literally.  Also, the regular
   expression special characters are matched literally in operator name
   patterns (i.e., the argument of <code class="literal">\do</code>).
  </p></div></div><div class="refsect2" id="id-1.9.4.18.8.5"><h3>Advanced Features</h3><div class="refsect3" id="APP-PSQL-VARIABLES"><h4>Variables</h4><p>
    <span class="application">psql</span> provides variable substitution
    features similar to common Unix command shells.
    Variables are simply name/value pairs, where the value
    can be any string of any length.  The name must consist of letters
    (including non-Latin letters), digits, and underscores.
    </p><p>
    To set a variable, use the <span class="application">psql</span> meta-command
    <code class="command">\set</code>.  For example,
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\set foo bar</code></strong>
</pre><p>
    sets the variable <code class="literal">foo</code> to the value
    <code class="literal">bar</code>. To retrieve the content of the variable, precede
    the name with a colon, for example:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\echo :foo</code></strong>
bar
</pre><p>
    This works in both regular SQL commands and meta-commands; there is
    more detail in <a class="xref" href="app-psql.html#APP-PSQL-INTERPOLATION" title="SQL Interpolation"><acronym class="acronym">SQL</acronym> Interpolation</a>, below.
    </p><p>
    If you call <code class="command">\set</code> without a second argument, the
    variable is set to an empty-string value. To unset (i.e., delete)
    a variable, use the command <code class="command">\unset</code>.  To show the
    values of all variables, call <code class="command">\set</code> without any argument.
    </p><div class="note"><h3 class="title">Note</h3><p>
    The arguments of <code class="command">\set</code> are subject to the same
    substitution rules as with other commands. Thus you can construct
    interesting references such as <code class="literal">\set :foo
    'something'</code> and get <span class="quote">“<span class="quote">soft links</span>”</span> or
    <span class="quote">“<span class="quote">variable variables</span>”</span> of <span class="productname">Perl</span>
    or <span class="productname"><acronym class="acronym">PHP</acronym></span> fame,
    respectively. Unfortunately (or fortunately?), there is no way to do
    anything useful with these constructs. On the other hand,
    <code class="literal">\set bar :foo</code> is a perfectly valid way to copy a
    variable.
    </p></div><p>
    A number of these variables are treated specially
    by <span class="application">psql</span>. They represent certain option
    settings that can be changed at run time by altering the value of
    the variable, or in some cases represent changeable state of
    <span class="application">psql</span>.
    By convention, all specially treated variables' names
    consist of all upper-case ASCII letters (and possibly digits and
    underscores). To ensure maximum compatibility in the future, avoid
    using such variable names for your own purposes.
   </p><p>
    Variables that control <span class="application">psql</span>'s behavior
    generally cannot be unset or set to invalid values.  An <code class="literal">\unset</code>
    command is allowed but is interpreted as setting the variable to its
    default value.  A <code class="literal">\set</code> command without a second argument is
    interpreted as setting the variable to <code class="literal">on</code>, for control
    variables that accept that value, and is rejected for others.  Also,
    control variables that accept the values <code class="literal">on</code>
    and <code class="literal">off</code> will also accept other common spellings of Boolean
    values, such as <code class="literal">true</code> and <code class="literal">false</code>.
   </p><p>
    The specially treated variables are:
   </p><div class="variablelist"><dl class="variablelist"><dt><span class="term">
       <code class="varname">AUTOCOMMIT</code>
       <a id="id-1.9.4.18.8.5.2.9.1.1.2" class="indexterm"></a>
      </span></dt><dd><p>
        When <code class="literal">on</code> (the default), each SQL command is automatically
        committed upon successful completion.  To postpone commit in this
        mode, you must enter a <code class="command">BEGIN</code> or <code class="command">START
        TRANSACTION</code> SQL command.  When <code class="literal">off</code> or unset, SQL
        commands are not committed until you explicitly issue
        <code class="command">COMMIT</code> or <code class="command">END</code>.  The autocommit-off
        mode works by issuing an implicit <code class="command">BEGIN</code> for you, just
        before any command that is not already in a transaction block and
        is not itself a <code class="command">BEGIN</code> or other transaction-control
        command, nor a command that cannot be executed inside a transaction
        block (such as <code class="command">VACUUM</code>).
        </p><div class="note"><h3 class="title">Note</h3><p>
         In autocommit-off mode, you must explicitly abandon any failed
         transaction by entering <code class="command">ABORT</code> or <code class="command">ROLLBACK</code>.
         Also keep in mind that if you exit the session
         without committing, your work will be lost.
        </p></div><div class="note"><h3 class="title">Note</h3><p>
         The autocommit-on mode is <span class="productname">PostgreSQL</span>'s traditional
         behavior, but autocommit-off is closer to the SQL spec.  If you
         prefer autocommit-off, you might wish to set it in the system-wide
         <code class="filename">psqlrc</code> file or your
         <code class="filename">~/.psqlrc</code> file.
        </p></div></dd><dt><span class="term"><code class="varname">COMP_KEYWORD_CASE</code></span></dt><dd><p>
        Determines which letter case to use when completing an SQL key word.
        If set to <code class="literal">lower</code> or <code class="literal">upper</code>, the
        completed word will be in lower or upper case, respectively.  If set
        to <code class="literal">preserve-lower</code>
        or <code class="literal">preserve-upper</code> (the default), the completed word
        will be in the case of the word already entered, but words being
        completed without anything entered will be in lower or upper case,
        respectively.
        </p></dd><dt><span class="term"><code class="varname">DBNAME</code></span></dt><dd><p>
        The name of the database you are currently connected to. This is
        set every time you connect to a database (including program
        start-up), but can be changed or unset.
        </p></dd><dt><span class="term"><code class="varname">ECHO</code></span></dt><dd><p>
        If set to <code class="literal">all</code>, all nonempty input lines are printed
        to standard output as they are read.  (This does not apply to lines
        read interactively.)  To select this behavior on program
        start-up, use the switch <code class="option">-a</code>. If set to
        <code class="literal">queries</code>,
        <span class="application">psql</span> prints each query to standard output
        as it is sent to the server. The switch to select this behavior is
        <code class="option">-e</code>. If set to <code class="literal">errors</code>, then only
        failed queries are displayed on standard error output. The switch
        for this behavior is <code class="option">-b</code>. If set to
        <code class="literal">none</code> (the default), then no queries are displayed.
        </p></dd><dt><span class="term"><code class="varname">ECHO_HIDDEN</code></span></dt><dd><p>
        When this variable is set to <code class="literal">on</code> and a backslash command
        queries the database, the query is first shown.
        This feature helps you to study
        <span class="productname">PostgreSQL</span> internals and provide
        similar functionality in your own programs. (To select this behavior
        on program start-up, use the switch <code class="option">-E</code>.)  If you set
        this variable to the value <code class="literal">noexec</code>, the queries are
        just shown but are not actually sent to the server and executed.
        The default value is <code class="literal">off</code>.
        </p></dd><dt><span class="term"><code class="varname">ENCODING</code></span></dt><dd><p>
        The current client character set encoding.
        This is set every time you connect to a database (including
        program start-up), and when you change the encoding
        with <code class="literal">\encoding</code>, but it can be changed or unset.
        </p></dd><dt><span class="term"><code class="varname">ERROR</code></span></dt><dd><p>
         <code class="literal">true</code> if the last SQL query failed, <code class="literal">false</code> if
         it succeeded.  See also <code class="varname">SQLSTATE</code>.
        </p></dd><dt><span class="term"><code class="varname">FETCH_COUNT</code></span></dt><dd><p>
        If this variable is set to an integer value greater than zero,
        the results of <code class="command">SELECT</code> queries are fetched
        and displayed in groups of that many rows, rather than the
        default behavior of collecting the entire result set before
        display.  Therefore only a
        limited amount of memory is used, regardless of the size of
        the result set.  Settings of 100 to 1000 are commonly used
        when enabling this feature.
        Keep in mind that when using this feature, a query might
        fail after having already displayed some rows.
        </p><div class="tip"><h3 class="title">Tip</h3><p>
        Although you can use any output format with this feature,
        the default <code class="literal">aligned</code> format tends to look bad
        because each group of <code class="varname">FETCH_COUNT</code> rows
        will be formatted separately, leading to varying column
        widths across the row groups.  The other output formats work better.
        </p></div></dd><dt><span class="term"><code class="varname">HIDE_TABLEAM</code></span></dt><dd><p>
         If this variable is set to <code class="literal">true</code>, a table's access
         method details are not displayed. This is mainly useful for
         regression tests.
        </p></dd><dt><span class="term"><code class="varname">HISTCONTROL</code></span></dt><dd><p>
         If this variable is set to <code class="literal">ignorespace</code>,
         lines which begin with a space are not entered into the history
         list. If set to a value of <code class="literal">ignoredups</code>, lines
         matching the previous history line are not entered. A value of
         <code class="literal">ignoreboth</code> combines the two options. If
         set to <code class="literal">none</code> (the default), all lines
         read in interactive mode are saved on the history list.
        </p><div class="note"><h3 class="title">Note</h3><p>
        This feature was shamelessly plagiarized from
        <span class="application">Bash</span>.
        </p></div></dd><dt><span class="term"><code class="varname">HISTFILE</code></span></dt><dd><p>
        The file name that will be used to store the history list.  If unset,
        the file name is taken from the <code class="envar">PSQL_HISTORY</code>
        environment variable.  If that is not set either, the default
        is <code class="filename">~/.psql_history</code>,
        or <code class="filename">%APPDATA%\postgresql\psql_history</code> on Windows.
        For example, putting:
</p><pre class="programlisting">
\set HISTFILE ~/.psql_history- :DBNAME
</pre><p>
        in <code class="filename">~/.psqlrc</code> will cause
        <span class="application">psql</span> to maintain a separate history for
        each database.
        </p><div class="note"><h3 class="title">Note</h3><p>
        This feature was shamelessly plagiarized from
        <span class="application">Bash</span>.
        </p></div></dd><dt><span class="term"><code class="varname">HISTSIZE</code></span></dt><dd><p>
        The maximum number of commands to store in the command history
        (default 500).  If set to a negative value, no limit is applied.
        </p><div class="note"><h3 class="title">Note</h3><p>
        This feature was shamelessly plagiarized from
        <span class="application">Bash</span>.
        </p></div></dd><dt><span class="term"><code class="varname">HOST</code></span></dt><dd><p>
        The database server host you are currently connected to. This is
        set every time you connect to a database (including program
        start-up), but can be changed or unset.
        </p></dd><dt><span class="term"><code class="varname">IGNOREEOF</code></span></dt><dd><p>
         If set to 1 or less, sending an <acronym class="acronym">EOF</acronym> character (usually
         <span class="keycap"><strong>Control</strong></span>+<span class="keycap"><strong>D</strong></span>)
         to an interactive session of <span class="application">psql</span>
         will terminate the application.  If set to a larger numeric value,
         that many consecutive <acronym class="acronym">EOF</acronym> characters must be typed to
         make an interactive session terminate.  If the variable is set to a
         non-numeric value, it is interpreted as 10.  The default is 0.
        </p><div class="note"><h3 class="title">Note</h3><p>
        This feature was shamelessly plagiarized from
        <span class="application">Bash</span>.
        </p></div></dd><dt><span class="term"><code class="varname">LASTOID</code></span></dt><dd><p>
        The value of the last affected OID, as returned from an
        <code class="command">INSERT</code> or <code class="command">\lo_import</code>
        command. This variable is only guaranteed to be valid until
        after the result of the next <acronym class="acronym">SQL</acronym> command has
        been displayed.
        <span class="productname">PostgreSQL</span> servers since version 12 do not
        support OID system columns anymore, thus LASTOID will always be 0
        following <code class="command">INSERT</code> when targeting such servers.
        </p></dd><dt><span class="term"><code class="varname">LAST_ERROR_MESSAGE</code><br /></span><span class="term"><code class="varname">LAST_ERROR_SQLSTATE</code></span></dt><dd><p>
         The primary error message and associated SQLSTATE code for the most
         recent failed query in the current <span class="application">psql</span> session, or
         an empty string and <code class="literal">00000</code> if no error has occurred in
         the current session.
        </p></dd><dt><span class="term">
       <code class="varname">ON_ERROR_ROLLBACK</code>
       <a id="id-1.9.4.18.8.5.2.9.17.1.2" class="indexterm"></a>
      </span></dt><dd><p>
        When set to <code class="literal">on</code>, if a statement in a transaction block
        generates an error, the error is ignored and the transaction
        continues. When set to <code class="literal">interactive</code>, such errors are only
        ignored in interactive sessions, and not when reading script
        files. When set to <code class="literal">off</code> (the default), a statement in a
        transaction block that generates an error aborts the entire
        transaction. The error rollback mode works by issuing an
        implicit <code class="command">SAVEPOINT</code> for you, just before each command
        that is in a transaction block, and then rolling back to the
        savepoint if the command fails.
        </p></dd><dt><span class="term"><code class="varname">ON_ERROR_STOP</code></span></dt><dd><p>
        By default, command processing continues after an error.  When this
        variable is set to <code class="literal">on</code>, processing will instead stop
        immediately.  In interactive mode,
        <span class="application">psql</span> will return to the command prompt;
        otherwise, <span class="application">psql</span> will exit, returning
        error code 3 to distinguish this case from fatal error
        conditions, which are reported using error code 1.  In either case,
        any currently running scripts (the top-level script, if any, and any
        other scripts which it may have in invoked) will be terminated
        immediately.  If the top-level command string contained multiple SQL
        commands, processing will stop with the current command.
        </p></dd><dt><span class="term"><code class="varname">PORT</code></span></dt><dd><p>
        The database server port to which you are currently connected.
        This is set every time you connect to a database (including
        program start-up), but can be changed or unset.
        </p></dd><dt><span class="term"><code class="varname">PROMPT1</code><br /></span><span class="term"><code class="varname">PROMPT2</code><br /></span><span class="term"><code class="varname">PROMPT3</code></span></dt><dd><p>
        These specify what the prompts <span class="application">psql</span>
        issues should look like. See <a class="xref" href="app-psql.html#APP-PSQL-PROMPTING" title="Prompting">Prompting</a> below.
        </p></dd><dt><span class="term"><code class="varname">QUIET</code></span></dt><dd><p>
        Setting this variable to <code class="literal">on</code> is equivalent to the command
        line option <code class="option">-q</code>. It is probably not too useful in
        interactive mode.
        </p></dd><dt><span class="term"><code class="varname">ROW_COUNT</code></span></dt><dd><p>
         The number of rows returned or affected by the last SQL query, or 0
         if the query failed or did not report a row count.
        </p></dd><dt><span class="term"><code class="varname">SERVER_VERSION_NAME</code><br /></span><span class="term"><code class="varname">SERVER_VERSION_NUM</code></span></dt><dd><p>
        The server's version number as a string, for
        example <code class="literal">9.6.2</code>, <code class="literal">10.1</code> or <code class="literal">11beta1</code>,
        and in numeric form, for
        example <code class="literal">90602</code> or <code class="literal">100001</code>.
        These are set every time you connect to a database
        (including program start-up), but can be changed or unset.
        </p></dd><dt><span class="term"><code class="varname">SHOW_CONTEXT</code></span></dt><dd><p>
        This variable can be set to the
        values <code class="literal">never</code>, <code class="literal">errors</code>, or <code class="literal">always</code>
        to control whether <code class="literal">CONTEXT</code> fields are displayed in
        messages from the server. The default is <code class="literal">errors</code> (meaning
        that context will be shown in error messages, but not in notice or
        warning messages).  This setting has no effect
        when <code class="varname">VERBOSITY</code> is set to <code class="literal">terse</code>
        or <code class="literal">sqlstate</code>.
        (See also <code class="command">\errverbose</code>, for use when you want a verbose
        version of the error you just got.)
        </p></dd><dt><span class="term"><code class="varname">SINGLELINE</code></span></dt><dd><p>
        Setting this variable to <code class="literal">on</code> is equivalent to the command
        line option <code class="option">-S</code>.
        </p></dd><dt><span class="term"><code class="varname">SINGLESTEP</code></span></dt><dd><p>
        Setting this variable to <code class="literal">on</code> is equivalent to the command
        line option <code class="option">-s</code>.
        </p></dd><dt><span class="term"><code class="varname">SQLSTATE</code></span></dt><dd><p>
         The error code (see <a class="xref" href="errcodes-appendix.html" title="Appendix A. PostgreSQL Error Codes">Appendix A</a>) associated
         with the last SQL query's failure, or <code class="literal">00000</code> if it
         succeeded.
        </p></dd><dt><span class="term"><code class="varname">USER</code></span></dt><dd><p>
        The database user you are currently connected as. This is set
        every time you connect to a database (including program
        start-up), but can be changed or unset.
        </p></dd><dt><span class="term"><code class="varname">VERBOSITY</code></span></dt><dd><p>
        This variable can be set to the values <code class="literal">default</code>,
        <code class="literal">verbose</code>, <code class="literal">terse</code>,
        or <code class="literal">sqlstate</code> to control the verbosity of error
        reports.
        (See also <code class="command">\errverbose</code>, for use when you want a verbose
        version of the error you just got.)
        </p></dd><dt><span class="term"><code class="varname">VERSION</code><br /></span><span class="term"><code class="varname">VERSION_NAME</code><br /></span><span class="term"><code class="varname">VERSION_NUM</code></span></dt><dd><p>
        These variables are set at program start-up to reflect
        <span class="application">psql</span>'s version, respectively as a verbose string,
        a short string (e.g., <code class="literal">9.6.2</code>, <code class="literal">10.1</code>,
        or <code class="literal">11beta1</code>), and a number (e.g., <code class="literal">90602</code>
        or <code class="literal">100001</code>).  They can be changed or unset.
        </p></dd></dl></div></div><div class="refsect3" id="APP-PSQL-INTERPOLATION"><h4><acronym class="acronym">SQL</acronym> Interpolation</h4><p>
    A key feature of <span class="application">psql</span>
    variables is that you can substitute (<span class="quote">“<span class="quote">interpolate</span>”</span>)
    them into regular <acronym class="acronym">SQL</acronym> statements, as well as the
    arguments of meta-commands.  Furthermore,
    <span class="application">psql</span> provides facilities for
    ensuring that variable values used as SQL literals and identifiers are
    properly quoted.  The syntax for interpolating a value without
    any quoting is to prepend the variable name with a colon
    (<code class="literal">:</code>).  For example,
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\set foo 'my_table'</code></strong>
testdb=&gt; <strong class="userinput"><code>SELECT * FROM :foo;</code></strong>
</pre><p>
    would query the table <code class="literal">my_table</code>. Note that this
    may be unsafe: the value of the variable is copied literally, so it can
    contain unbalanced quotes, or even backslash commands. You must make sure
    that it makes sense where you put it.
    </p><p>
    When a value is to be used as an SQL literal or identifier, it is
    safest to arrange for it to be quoted.  To quote the value of
    a variable as an SQL literal, write a colon followed by the variable
    name in single quotes.  To quote the value as an SQL identifier, write
    a colon followed by the variable name in double quotes.
    These constructs deal correctly with quotes and other special
    characters embedded within the variable value.
    The previous example would be more safely written this way:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\set foo 'my_table'</code></strong>
testdb=&gt; <strong class="userinput"><code>SELECT * FROM :"foo";</code></strong>
</pre><p>
    </p><p>
    Variable interpolation will not be performed within quoted
    <acronym class="acronym">SQL</acronym> literals and identifiers.  Therefore, a
    construction such as <code class="literal">':foo'</code> doesn't work to produce a quoted
    literal from a variable's value (and it would be unsafe if it did work,
    since it wouldn't correctly handle quotes embedded in the value).
    </p><p>
    One example use of this mechanism is to
    copy the contents of a file into a table column.
    First load the file into a variable and then interpolate the variable's
    value as a quoted string:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\set content `cat my_file.txt`</code></strong>
testdb=&gt; <strong class="userinput"><code>INSERT INTO my_table VALUES (:'content');</code></strong>
</pre><p>
    (Note that this still won't work if <code class="filename">my_file.txt</code> contains NUL bytes.
    <span class="application">psql</span> does not support embedded NUL bytes in variable values.)
    </p><p>
    Since colons can legally appear in SQL commands, an apparent attempt
    at interpolation (that is, <code class="literal">:name</code>,
    <code class="literal">:'name'</code>, or <code class="literal">:"name"</code>) is not
    replaced unless the named variable is currently set. In any case, you
    can escape a colon with a backslash to protect it from substitution.
    </p><p>
    The <code class="literal">:{?<em class="replaceable"><code>name</code></em>}</code> special syntax returns TRUE
    or FALSE depending on whether the variable exists or not, and is thus
    always substituted, unless the colon is backslash-escaped.
    </p><p>
    The colon syntax for variables is standard <acronym class="acronym">SQL</acronym> for
    embedded query languages, such as <span class="application">ECPG</span>.
    The colon syntaxes for array slices and type casts are
    <span class="productname">PostgreSQL</span> extensions, which can sometimes
    conflict with the standard usage.  The colon-quote syntax for escaping a
    variable's value as an SQL literal or identifier is a
    <span class="application">psql</span> extension.
    </p></div><div class="refsect3" id="APP-PSQL-PROMPTING"><h4>Prompting</h4><p>
    The prompts <span class="application">psql</span> issues can be customized
    to your preference. The three variables <code class="varname">PROMPT1</code>,
    <code class="varname">PROMPT2</code>, and <code class="varname">PROMPT3</code> contain strings
    and special escape sequences that describe the appearance of the
    prompt. Prompt 1 is the normal prompt that is issued when
    <span class="application">psql</span> requests a new command. Prompt 2 is
    issued when more input is expected during command entry, for example
    because the command was not terminated with a semicolon or a quote
    was not closed.
    Prompt 3 is issued when you are running an <acronym class="acronym">SQL</acronym>
    <code class="command">COPY FROM STDIN</code> command and you need to type in
    a row value on the terminal.
    </p><p>
    The value of the selected prompt variable is printed literally,
    except where a percent sign (<code class="literal">%</code>) is encountered.
    Depending on the next character, certain other text is substituted
    instead. Defined substitutions are:

    </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">%M</code></span></dt><dd><p>
          The full host name (with domain name) of the database server,
          or <code class="literal">[local]</code> if the connection is over a Unix
          domain socket, or
          <code class="literal">[local:<em class="replaceable"><code>/dir/name</code></em>]</code>,
          if the Unix domain socket is not at the compiled in default
          location.
        </p></dd><dt><span class="term"><code class="literal">%m</code></span></dt><dd><p>
          The host name of the database server, truncated at the
          first dot, or <code class="literal">[local]</code> if the connection is
          over a Unix domain socket.
         </p></dd><dt><span class="term"><code class="literal">%&gt;</code></span></dt><dd><p>The port number at which the database server is listening.</p></dd><dt><span class="term"><code class="literal">%n</code></span></dt><dd><p>
          The database session user name.  (The expansion of this
          value might change during a database session as the result
          of the command <code class="command">SET SESSION
          AUTHORIZATION</code>.)
         </p></dd><dt><span class="term"><code class="literal">%/</code></span></dt><dd><p>The name of the current database.</p></dd><dt><span class="term"><code class="literal">%~</code></span></dt><dd><p>Like <code class="literal">%/</code>, but the output is <code class="literal">~</code>
         (tilde) if the database is your default database.</p></dd><dt><span class="term"><code class="literal">%#</code></span></dt><dd><p>
          If the session user is a database superuser, then a
          <code class="literal">#</code>, otherwise a <code class="literal">&gt;</code>.
          (The expansion of this value might change during a database
          session as the result of the command <code class="command">SET SESSION
          AUTHORIZATION</code>.)
         </p></dd><dt><span class="term"><code class="literal">%p</code></span></dt><dd><p>The process ID of the backend currently connected to.</p></dd><dt><span class="term"><code class="literal">%R</code></span></dt><dd><p>
        In prompt 1 normally <code class="literal">=</code>,
        but <code class="literal">@</code> if the session is in an inactive branch of a
        conditional block, or <code class="literal">^</code> if in single-line mode,
        or <code class="literal">!</code> if the session is disconnected from the
        database (which can happen if <code class="command">\connect</code> fails).
        In prompt 2 <code class="literal">%R</code> is replaced by a character that
        depends on why <span class="application">psql</span> expects more input:
        <code class="literal">-</code> if the command simply wasn't terminated yet,
        but <code class="literal">*</code> if there is an unfinished
        <code class="literal">/* ... */</code> comment,
        a single quote if there is an unfinished quoted string,
        a double quote if there is an unfinished quoted identifier,
        a dollar sign if there is an unfinished dollar-quoted string,
        or <code class="literal">(</code> if there is an unmatched left parenthesis.
        In prompt 3 <code class="literal">%R</code> doesn't produce anything.
        </p></dd><dt><span class="term"><code class="literal">%x</code></span></dt><dd><p>
        Transaction status: an empty string when not in a transaction
        block, or <code class="literal">*</code> when in a transaction block, or
        <code class="literal">!</code> when in a failed transaction block, or <code class="literal">?</code>
        when the transaction state is indeterminate (for example, because
        there is no connection).
        </p></dd><dt><span class="term"><code class="literal">%l</code></span></dt><dd><p>
          The line number inside the current statement, starting from <code class="literal">1</code>.
         </p></dd><dt><span class="term"><code class="literal">%</code><em class="replaceable"><code>digits</code></em></span></dt><dd><p>
        The character with the indicated octal code is substituted.
        </p></dd><dt><span class="term"><code class="literal">%:</code><em class="replaceable"><code>name</code></em><code class="literal">:</code></span></dt><dd><p>
        The value of the <span class="application">psql</span> variable
        <em class="replaceable"><code>name</code></em>. See the
        section <a class="xref" href="app-psql.html#APP-PSQL-VARIABLES" title="Variables">Variables</a> for details.
        </p></dd><dt><span class="term"><code class="literal">%`</code><em class="replaceable"><code>command</code></em><code class="literal">`</code></span></dt><dd><p>
        The output of <em class="replaceable"><code>command</code></em>, similar to ordinary
        <span class="quote">“<span class="quote">back-tick</span>”</span> substitution.
        </p></dd><dt><span class="term"><code class="literal">%[</code> ... <code class="literal">%]</code></span></dt><dd><p>
         Prompts can contain terminal control characters which, for
         example, change the color, background, or style of the prompt
         text, or change the title of the terminal window. In order for
         the line editing features of <span class="application">Readline</span> to work properly, these
         non-printing control characters must be designated as invisible
         by surrounding them with <code class="literal">%[</code> and
         <code class="literal">%]</code>. Multiple pairs of these can occur within
         the prompt.  For example:
</p><pre class="programlisting">
testdb=&gt; \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%]%# '
</pre><p>
         results in a boldfaced (<code class="literal">1;</code>) yellow-on-black
         (<code class="literal">33;40</code>) prompt on VT100-compatible, color-capable
         terminals.
        </p></dd></dl></div><p>

    To insert a percent sign into your prompt, write
    <code class="literal">%%</code>. The default prompts are
    <code class="literal">'%/%R%# '</code> for prompts 1 and 2, and
    <code class="literal">'&gt;&gt; '</code> for prompt 3.
    </p><div class="note"><h3 class="title">Note</h3><p>
    This feature was shamelessly plagiarized from
    <span class="application">tcsh</span>.
    </p></div></div><div class="refsect3" id="id-1.9.4.18.8.5.5"><h4>Command-Line Editing</h4><p>
    <span class="application">psql</span> supports the <span class="application">Readline</span>
    library for convenient line editing and retrieval. The command
    history is automatically saved when <span class="application">psql</span>
    exits and is reloaded when
    <span class="application">psql</span> starts up. Tab-completion is also
    supported, although the completion logic makes no claim to be an
    <acronym class="acronym">SQL</acronym> parser.  The queries generated by tab-completion
    can also interfere with other SQL commands, e.g. <code class="literal">SET
    TRANSACTION ISOLATION LEVEL</code>.
    If for some reason you do not like the tab completion, you
    can turn it off by putting this in a file named
    <code class="filename">.inputrc</code> in your home directory:
</p><pre class="programlisting">
$if psql
set disable-completion on
$endif
</pre><p>
    (This is not a <span class="application">psql</span> but a
    <span class="application">Readline</span> feature. Read its documentation
    for further details.)
    </p></div></div></div><div class="refsect1" id="APP-PSQL-ENVIRONMENT"><h2>Environment</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">COLUMNS</code></span></dt><dd><p>
      If <code class="literal">\pset columns</code> is zero, controls the
      width for the <code class="literal">wrapped</code> format and width for determining
      if wide output requires the pager or should be switched to the
      vertical format in expanded auto mode.
     </p></dd><dt><span class="term"><code class="envar">PGDATABASE</code><br /></span><span class="term"><code class="envar">PGHOST</code><br /></span><span class="term"><code class="envar">PGPORT</code><br /></span><span class="term"><code class="envar">PGUSER</code></span></dt><dd><p>
      Default connection parameters (see <a class="xref" href="libpq-envars.html" title="33.14. Environment Variables">Section 33.14</a>).
     </p></dd><dt><span class="term"><code class="envar">PG_COLOR</code></span></dt><dd><p>
      Specifies whether to use color in diagnostic messages. Possible values
      are <code class="literal">always</code>, <code class="literal">auto</code> and
      <code class="literal">never</code>.
     </p></dd><dt><span class="term"><code class="envar">PSQL_EDITOR</code><br /></span><span class="term"><code class="envar">EDITOR</code><br /></span><span class="term"><code class="envar">VISUAL</code></span></dt><dd><p>
      Editor used by the <code class="command">\e</code>, <code class="command">\ef</code>,
      and <code class="command">\ev</code> commands.
      These variables are examined in the order listed;
      the first that is set is used.
      If none of them is set, the default is to use <code class="filename">vi</code>
      on Unix systems or <code class="filename">notepad.exe</code> on Windows systems.
     </p></dd><dt><span class="term"><code class="envar">PSQL_EDITOR_LINENUMBER_ARG</code></span></dt><dd><p>
      When <code class="command">\e</code>, <code class="command">\ef</code>, or
      <code class="command">\ev</code> is used
      with a line number argument, this variable specifies the
      command-line argument used to pass the starting line number to
      the user's editor.  For editors such as <span class="productname">Emacs</span> or
      <span class="productname">vi</span>, this is a plus sign.  Include a trailing
      space in the value of the variable if there needs to be space
      between the option name and the line number.  Examples:
</p><pre class="programlisting">
PSQL_EDITOR_LINENUMBER_ARG='+'
PSQL_EDITOR_LINENUMBER_ARG='--line '
</pre><p>
     </p><p>
      The default is <code class="literal">+</code> on Unix systems
      (corresponding to the default editor <code class="filename">vi</code>,
      and useful for many other common editors); but there is no
      default on Windows systems.
     </p></dd><dt><span class="term"><code class="envar">PSQL_HISTORY</code></span></dt><dd><p>
      Alternative location for the command history file. Tilde (<code class="literal">~</code>) expansion is performed.
     </p></dd><dt><span class="term"><code class="envar">PSQL_PAGER</code><br /></span><span class="term"><code class="envar">PAGER</code></span></dt><dd><p>
      If a query's results do not fit on the screen, they are piped
      through this command. Typical values are <code class="literal">more</code>
      or <code class="literal">less</code>.
      Use of the pager can be disabled by setting <code class="envar">PSQL_PAGER</code>
      or <code class="envar">PAGER</code> to an empty string, or by adjusting the
      pager-related options of the <code class="command">\pset</code> command.
      These variables are examined in the order listed;
      the first that is set is used.
      If none of them is set, the default is to use <code class="literal">more</code> on most
      platforms, but <code class="literal">less</code> on Cygwin.
     </p></dd><dt><span class="term"><code class="envar">PSQLRC</code></span></dt><dd><p>
      Alternative location of the user's <code class="filename">.psqlrc</code> file. Tilde (<code class="literal">~</code>) expansion is performed.
     </p></dd><dt><span class="term"><code class="envar">SHELL</code></span></dt><dd><p>
      Command executed by the <code class="command">\!</code> command.
     </p></dd><dt><span class="term"><code class="envar">TMPDIR</code></span></dt><dd><p>
      Directory for storing temporary files.  The default is
      <code class="filename">/tmp</code>.
     </p></dd></dl></div><p>
   This utility, like most other <span class="productname">PostgreSQL</span> utilities,
   also uses the environment variables supported by <span class="application">libpq</span>
   (see <a class="xref" href="libpq-envars.html" title="33.14. Environment Variables">Section 33.14</a>).
  </p></div><div class="refsect1" id="id-1.9.4.18.10"><h2>Files</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="filename">psqlrc</code> and <code class="filename">~/.psqlrc</code></span></dt><dd><p>
     Unless it is passed an <code class="option">-X</code> option,
     <span class="application">psql</span> attempts to read and execute commands
     from the system-wide startup file (<code class="filename">psqlrc</code>) and then
     the user's personal startup file (<code class="filename">~/.psqlrc</code>), after
     connecting to the database but before accepting normal commands.
     These files can be used to set up the client and/or the server to taste,
     typically with <code class="command">\set</code> and <code class="command">SET</code>
     commands.
    </p><p>
     The system-wide startup file is named <code class="filename">psqlrc</code> and is
     sought in the installation's <span class="quote">“<span class="quote">system configuration</span>”</span> directory,
     which is most reliably identified by running <code class="literal">pg_config
     --sysconfdir</code>.  By default this directory will be <code class="filename">../etc/</code>
     relative to the directory containing
     the <span class="productname">PostgreSQL</span> executables.  The name of this
     directory can be set explicitly via the <code class="envar">PGSYSCONFDIR</code>
     environment variable.
    </p><p>
     The user's personal startup file is named <code class="filename">.psqlrc</code>
     and is sought in the invoking user's home directory.  On Windows, which
     lacks such a concept, the personal startup file is named
     <code class="filename">%APPDATA%\postgresql\psqlrc.conf</code>.
     The location of the user's startup file can be set explicitly via
     the <code class="envar">PSQLRC</code> environment variable.
    </p><p>
     Both the system-wide startup file and the user's personal startup file
     can be made <span class="application">psql</span>-version-specific
     by appending a dash and the <span class="productname">PostgreSQL</span>
     major or minor release number to the file name,
     for example <code class="filename">~/.psqlrc-9.2</code> or
     <code class="filename">~/.psqlrc-9.2.5</code>.  The most specific
     version-matching file will be read in preference to a
     non-version-specific file.
    </p></dd><dt><span class="term"><code class="filename">.psql_history</code></span></dt><dd><p>
     The command-line history is stored in the file
     <code class="filename">~/.psql_history</code>, or
     <code class="filename">%APPDATA%\postgresql\psql_history</code> on Windows.
    </p><p>
     The location of the history file can be set explicitly via
     the <code class="varname">HISTFILE</code> <span class="application">psql</span> variable or
     the <code class="envar">PSQL_HISTORY</code> environment variable.
    </p></dd></dl></div></div><div class="refsect1" id="id-1.9.4.18.11"><h2>Notes</h2><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><span class="application">psql</span> works best with servers of the same
       or an older major version.  Backslash commands are particularly likely
       to fail if the server is of a newer version than <span class="application">psql</span>
       itself.  However, backslash commands of the <code class="literal">\d</code> family should
       work with servers of versions back to 7.4, though not necessarily with
       servers newer than <span class="application">psql</span> itself.  The general
       functionality of running SQL commands and displaying query results
       should also work with servers of a newer major version, but this cannot
       be guaranteed in all cases.
      </p><p>
       If you want to use <span class="application">psql</span> to connect to several
       servers of different major versions, it is recommended that you use the
       newest version of <span class="application">psql</span>.  Alternatively, you
       can keep around a copy of <span class="application">psql</span> from each
       major version and be sure to use the version that matches the
       respective server.  But in practice, this additional complication should
       not be necessary.
      </p></li><li class="listitem"><p>
       Before <span class="productname">PostgreSQL</span> 9.6,
       the <code class="option">-c</code> option implied <code class="option">-X</code>
       (<code class="option">--no-psqlrc</code>); this is no longer the case.
      </p></li><li class="listitem"><p>
       Before <span class="productname">PostgreSQL</span> 8.4,
       <span class="application">psql</span> allowed the
       first argument of a single-letter backslash command to start
       directly after the command, without intervening whitespace.
       Now, some whitespace is required.
      </p></li></ul></div></div><div class="refsect1" id="id-1.9.4.18.12"><h2>Notes for Windows Users</h2><p>
  <span class="application">psql</span> is built as a <span class="quote">“<span class="quote">console
  application</span>”</span>.  Since the Windows console windows use a different
  encoding than the rest of the system, you must take special care
  when using 8-bit characters within <span class="application">psql</span>.
  If <span class="application">psql</span> detects a problematic
  console code page, it will warn you at startup. To change the
  console code page, two things are necessary:

   </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
      Set the code page by entering <strong class="userinput"><code>cmd.exe /c chcp
      1252</code></strong>. (1252 is a code page that is appropriate for
      German; replace it with your value.) If you are using Cygwin,
      you can put this command in <code class="filename">/etc/profile</code>.
     </p></li><li class="listitem"><p>
      Set the console font to <code class="literal">Lucida Console</code>, because the
      raster font does not work with the ANSI code page.
     </p></li></ul></div></div><div class="refsect1" id="APP-PSQL-EXAMPLES"><h2>Examples</h2><p>
  The first example shows how to spread a command over several lines of
  input. Notice the changing prompt:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>CREATE TABLE my_table (</code></strong>
testdb(&gt; <strong class="userinput"><code> first integer not null default 0,</code></strong>
testdb(&gt; <strong class="userinput"><code> second text)</code></strong>
testdb-&gt; <strong class="userinput"><code>;</code></strong>
CREATE TABLE
</pre><p>
  Now look at the table definition again:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\d my_table</code></strong>
              Table "public.my_table"
 Column |  Type   | Collation | Nullable | Default
--------+---------+-----------+----------+---------
 first  | integer |           | not null | 0
 second | text    |           |          | 
</pre><p>
  Now we change the prompt to something more interesting:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>\set PROMPT1 '%n@%m %~%R%# '</code></strong>
peter@localhost testdb=&gt;
</pre><p>
  Let's assume you have filled the table with data and want to take a
  look at it:
</p><pre class="programlisting">
peter@localhost testdb=&gt; SELECT * FROM my_table;
 first | second
-------+--------
     1 | one
     2 | two
     3 | three
     4 | four
(4 rows)

</pre><p>
  You can display tables in different ways by using the
  <code class="command">\pset</code> command:
</p><pre class="programlisting">
peter@localhost testdb=&gt; <strong class="userinput"><code>\pset border 2</code></strong>
Border style is 2.
peter@localhost testdb=&gt; <strong class="userinput"><code>SELECT * FROM my_table;</code></strong>
+-------+--------+
| first | second |
+-------+--------+
|     1 | one    |
|     2 | two    |
|     3 | three  |
|     4 | four   |
+-------+--------+
(4 rows)

peter@localhost testdb=&gt; <strong class="userinput"><code>\pset border 0</code></strong>
Border style is 0.
peter@localhost testdb=&gt; <strong class="userinput"><code>SELECT * FROM my_table;</code></strong>
first second
----- ------
    1 one
    2 two
    3 three
    4 four
(4 rows)

peter@localhost testdb=&gt; <strong class="userinput"><code>\pset border 1</code></strong>
Border style is 1.
peter@localhost testdb=&gt; <strong class="userinput"><code>\pset format csv</code></strong>
Output format is csv.
peter@localhost testdb=&gt; <strong class="userinput"><code>\pset tuples_only</code></strong>
Tuples only is on.
peter@localhost testdb=&gt; <strong class="userinput"><code>SELECT second, first FROM my_table;</code></strong>
one,1
two,2
three,3
four,4
peter@localhost testdb=&gt; <strong class="userinput"><code>\pset format unaligned</code></strong>
Output format is unaligned.
peter@localhost testdb=&gt; <strong class="userinput"><code>\pset fieldsep '\t'</code></strong>
Field separator is "    ".
peter@localhost testdb=&gt; <strong class="userinput"><code>SELECT second, first FROM my_table;</code></strong>
one     1
two     2
three   3
four    4
</pre><p>
  Alternatively, use the short commands:
</p><pre class="programlisting">
peter@localhost testdb=&gt; <strong class="userinput"><code>\a \t \x</code></strong>
Output format is aligned.
Tuples only is off.
Expanded display is on.
peter@localhost testdb=&gt; <strong class="userinput"><code>SELECT * FROM my_table;</code></strong>
-[ RECORD 1 ]-
first  | 1
second | one
-[ RECORD 2 ]-
first  | 2
second | two
-[ RECORD 3 ]-
first  | 3
second | three
-[ RECORD 4 ]-
first  | 4
second | four
</pre><p>
  When suitable, query results can be shown in a crosstab representation
  with the <code class="command">\crosstabview</code> command:
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>SELECT first, second, first &gt; 2 AS gt2 FROM my_table;</code></strong>
 first | second | gt2 
-------+--------+-----
     1 | one    | f
     2 | two    | f
     3 | three  | t
     4 | four   | t
(4 rows)

testdb=&gt; <strong class="userinput"><code>\crosstabview first second</code></strong>
 first | one | two | three | four 
-------+-----+-----+-------+------
     1 | f   |     |       | 
     2 |     | f   |       | 
     3 |     |     | t     | 
     4 |     |     |       | t
(4 rows)
</pre><p>

This second example shows a multiplication table with rows sorted in reverse
numerical order and columns with an independent, ascending numerical order.
</p><pre class="programlisting">
testdb=&gt; <strong class="userinput"><code>SELECT t1.first as "A", t2.first+100 AS "B", t1.first*(t2.first+100) as "AxB",</code></strong>
testdb(&gt; <strong class="userinput"><code>row_number() over(order by t2.first) AS ord</code></strong>
testdb(&gt; <strong class="userinput"><code>FROM my_table t1 CROSS JOIN my_table t2 ORDER BY 1 DESC</code></strong>
testdb(&gt; <strong class="userinput"><code>\crosstabview "A" "B" "AxB" ord</code></strong>
 A | 101 | 102 | 103 | 104 
---+-----+-----+-----+-----
 4 | 404 | 408 | 412 | 416
 3 | 303 | 306 | 309 | 312
 2 | 202 | 204 | 206 | 208
 1 | 101 | 102 | 103 | 104
(4 rows)
</pre><p>

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