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  1. <?xml version="1.0" encoding="UTF-8" standalone="no"?>

  2. <!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>19.8. Error Reporting and Logging</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="runtime-config-query.html" title="19.7. Query Planning" /><link rel="next" href="runtime-config-statistics.html" title="19.9. Run-time Statistics" /></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">19.8. Error Reporting and Logging</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="runtime-config-query.html" title="19.7. Query Planning">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="runtime-config.html" title="Chapter 19. Server Configuration">Up</a></td><th width="60%" align="center">Chapter 19. Server Configuration</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="runtime-config-statistics.html" title="19.9. Run-time Statistics">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RUNTIME-CONFIG-LOGGING"><div class="titlepage"><div><div><h2 class="title" style="clear: both">19.8. Error Reporting and Logging</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHERE">19.8.1. Where to Log</a></span></dt><dt><span class="sect2"><a href="runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHEN">19.8.2. When to Log</a></span></dt><dt><span class="sect2"><a href="runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHAT">19.8.3. What to Log</a></span></dt><dt><span class="sect2"><a href="runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-CSVLOG">19.8.4. Using CSV-Format Log Output</a></span></dt><dt><span class="sect2"><a href="runtime-config-logging.html#id-1.6.6.11.7">19.8.5. Process Title</a></span></dt></dl></div><a id="id-1.6.6.11.2" class="indexterm"></a><div class="sect2" id="RUNTIME-CONFIG-LOGGING-WHERE"><div class="titlepage"><div><div><h3 class="title">19.8.1. Where to Log</h3></div></div></div><a id="id-1.6.6.11.3.2" class="indexterm"></a><a id="id-1.6.6.11.3.3" class="indexterm"></a><div class="variablelist"><dl class="variablelist"><dt id="GUC-LOG-DESTINATION"><span class="term"><code class="varname">log_destination</code> (<code class="type">string</code>)

  3.       <a id="id-1.6.6.11.3.4.1.1.3" class="indexterm"></a>

  4.       </span></dt><dd><p>

  5.         <span class="productname">PostgreSQL</span> supports several methods

  6.          for logging server messages, including

  7.          <span class="systemitem">stderr</span>, <span class="systemitem">csvlog</span> and

  8.          <span class="systemitem">syslog</span>. On Windows,

  9.          <span class="systemitem">eventlog</span> is also supported. Set this

  10.          parameter to a list of desired log destinations separated by

  11.          commas. The default is to log to <span class="systemitem">stderr</span>

  12.          only.

  13.          This parameter can only be set in the <code class="filename">postgresql.conf</code>

  14.          file or on the server command line.

  15.        </p><p>

  16.         If <span class="systemitem">csvlog</span> is included in <code class="varname">log_destination</code>,

  17.         log entries are output in <span class="quote">“<span class="quote">comma separated

  18.         value</span>”</span> (<acronym class="acronym">CSV</acronym>) format, which is convenient for

  19.         loading logs into programs.

  20.         See <a class="xref" href="runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-CSVLOG" title="19.8.4. Using CSV-Format Log Output">Section 19.8.4</a> for details.

  21.         <a class="xref" href="runtime-config-logging.html#GUC-LOGGING-COLLECTOR">logging_collector</a> must be enabled to generate

  22.         CSV-format log output.

  23.        </p><p>

  24.         When either <span class="systemitem">stderr</span> or

  25.         <span class="systemitem">csvlog</span> are included, the file

  26.         <code class="filename">current_logfiles</code> is created to record the location

  27.         of the log file(s) currently in use by the logging collector and the

  28.         associated logging destination. This provides a convenient way to

  29.         find the logs currently in use by the instance. Here is an example of

  30.         this file's content:

  31. </p><pre class="programlisting">

  32. stderr log/postgresql.log

  33. csvlog log/postgresql.csv

  34. </pre><p>

  35. 

  36.         <code class="filename">current_logfiles</code> is recreated when a new log file

  37.         is created as an effect of rotation, and

  38.         when <code class="varname">log_destination</code> is reloaded.  It is removed when

  39.         neither <span class="systemitem">stderr</span>

  40.         nor <span class="systemitem">csvlog</span> are included

  41.         in <code class="varname">log_destination</code>, and when the logging collector is

  42.         disabled.

  43.        </p><div class="note"><h3 class="title">Note</h3><p>

  44.          On most Unix systems, you will need to alter the configuration of

  45.          your system's <span class="application">syslog</span> daemon in order

  46.          to make use of the <span class="systemitem">syslog</span> option for

  47.          <code class="varname">log_destination</code>.  <span class="productname">PostgreSQL</span>

  48.          can log to <span class="application">syslog</span> facilities

  49.          <code class="literal">LOCAL0</code> through <code class="literal">LOCAL7</code> (see <a class="xref" href="runtime-config-logging.html#GUC-SYSLOG-FACILITY">syslog_facility</a>), but the default

  50.          <span class="application">syslog</span> configuration on most platforms

  51.          will discard all such messages.  You will need to add something like:

  52. </p><pre class="programlisting">

  53. local0.*    /var/log/postgresql

  54. </pre><p>

  55.          to the  <span class="application">syslog</span> daemon's configuration file

  56.          to make it work.

  57.         </p><p>

  58.          On Windows, when you use the <code class="literal">eventlog</code>

  59.          option for <code class="varname">log_destination</code>, you should

  60.          register an event source and its library with the operating

  61.          system so that the Windows Event Viewer can display event

  62.          log messages cleanly.

  63.          See <a class="xref" href="event-log-registration.html" title="18.12. Registering Event Log on Windows">Section 18.12</a> for details.

  64.         </p></div></dd><dt id="GUC-LOGGING-COLLECTOR"><span class="term"><code class="varname">logging_collector</code> (<code class="type">boolean</code>)

  65.       <a id="id-1.6.6.11.3.4.2.1.3" class="indexterm"></a>

  66.       </span></dt><dd><p>

  67.          This parameter enables the <em class="firstterm">logging collector</em>, which

  68.          is a background process that captures log messages

  69.          sent to <span class="systemitem">stderr</span> and redirects them into log files.

  70.          This approach is often more useful than

  71.          logging to <span class="application">syslog</span>, since some types of messages

  72.          might not appear in <span class="application">syslog</span> output.  (One common

  73.          example is dynamic-linker failure messages; another is error messages

  74.          produced by scripts such as <code class="varname">archive_command</code>.)

  75.          This parameter can only be set at server start.

  76.        </p><div class="note"><h3 class="title">Note</h3><p>

  77.          It is possible to log to <span class="systemitem">stderr</span> without using the

  78.          logging collector; the log messages will just go to wherever the

  79.          server's <span class="systemitem">stderr</span> is directed.  However, that method is

  80.          only suitable for low log volumes, since it provides no convenient

  81.          way to rotate log files.  Also, on some platforms not using the

  82.          logging collector can result in lost or garbled log output, because

  83.          multiple processes writing concurrently to the same log file can

  84.          overwrite each other's output.

  85.         </p></div><div class="note"><h3 class="title">Note</h3><p>

  86.           The logging collector is designed to never lose messages.  This means

  87.           that in case of extremely high load, server processes could be

  88.           blocked while trying to send additional log messages when the

  89.           collector has fallen behind.  In contrast, <span class="application">syslog</span>

  90.           prefers to drop messages if it cannot write them, which means it

  91.           may fail to log some messages in such cases but it will not block

  92.           the rest of the system.

  93.         </p></div></dd><dt id="GUC-LOG-DIRECTORY"><span class="term"><code class="varname">log_directory</code> (<code class="type">string</code>)

  94.       <a id="id-1.6.6.11.3.4.3.1.3" class="indexterm"></a>

  95.       </span></dt><dd><p>

  96.         When <code class="varname">logging_collector</code> is enabled,

  97.         this parameter determines the directory in which log files will be created.

  98.         It can be specified as an absolute path, or relative to the

  99.         cluster data directory.

  100.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  101.         file or on the server command line.

  102.         The default is <code class="literal">log</code>.

  103.        </p></dd><dt id="GUC-LOG-FILENAME"><span class="term"><code class="varname">log_filename</code> (<code class="type">string</code>)

  104.       <a id="id-1.6.6.11.3.4.4.1.3" class="indexterm"></a>

  105.       </span></dt><dd><p>

  106.         When <code class="varname">logging_collector</code> is enabled,

  107.         this parameter sets the file names of the created log files.  The value

  108.         is treated as a <code class="function">strftime</code> pattern,

  109.         so <code class="literal">%</code>-escapes can be used to specify time-varying

  110.         file names.  (Note that if there are

  111.         any time-zone-dependent <code class="literal">%</code>-escapes, the computation

  112.         is done in the zone specified

  113.         by <a class="xref" href="runtime-config-logging.html#GUC-LOG-TIMEZONE">log_timezone</a>.)

  114.         The supported <code class="literal">%</code>-escapes are similar to those

  115.         listed in the Open Group's <a class="ulink" href="https://pubs.opengroup.org/onlinepubs/009695399/functions/strftime.html" target="_top">strftime

  116.         </a> specification.

  117.         Note that the system's <code class="function">strftime</code> is not used

  118.         directly, so platform-specific (nonstandard) extensions do not work.

  119.         The default is <code class="literal">postgresql-%Y-%m-%d_%H%M%S.log</code>.

  120.        </p><p>

  121.         If you specify a file name without escapes, you should plan to

  122.         use a log rotation utility to avoid eventually filling the

  123.         entire disk.  In releases prior to 8.4, if

  124.         no <code class="literal">%</code> escapes were

  125.         present, <span class="productname">PostgreSQL</span> would append

  126.         the epoch of the new log file's creation time, but this is no

  127.         longer the case.

  128.        </p><p>

  129.         If CSV-format output is enabled in <code class="varname">log_destination</code>,

  130.         <code class="literal">.csv</code> will be appended to the timestamped

  131.         log file name to create the file name for CSV-format output.

  132.         (If <code class="varname">log_filename</code> ends in <code class="literal">.log</code>, the suffix is

  133.         replaced instead.)

  134.        </p><p>

  135.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  136.         file or on the server command line.

  137.        </p></dd><dt id="GUC-LOG-FILE-MODE"><span class="term"><code class="varname">log_file_mode</code> (<code class="type">integer</code>)

  138.       <a id="id-1.6.6.11.3.4.5.1.3" class="indexterm"></a>

  139.       </span></dt><dd><p>

  140.         On Unix systems this parameter sets the permissions for log files

  141.         when <code class="varname">logging_collector</code> is enabled. (On Microsoft

  142.         Windows this parameter is ignored.)

  143.         The parameter value is expected to be a numeric mode

  144.         specified in the format accepted by the

  145.         <code class="function">chmod</code> and <code class="function">umask</code>

  146.         system calls.  (To use the customary octal format the number

  147.         must start with a <code class="literal">0</code> (zero).)

  148.        </p><p>

  149.         The default permissions are <code class="literal">0600</code>, meaning only the

  150.         server owner can read or write the log files.  The other commonly

  151.         useful setting is <code class="literal">0640</code>, allowing members of the owner's

  152.         group to read the files.  Note however that to make use of such a

  153.         setting, you'll need to alter <a class="xref" href="runtime-config-logging.html#GUC-LOG-DIRECTORY">log_directory</a> to

  154.         store the files somewhere outside the cluster data directory.  In

  155.         any case, it's unwise to make the log files world-readable, since

  156.         they might contain sensitive data.

  157.        </p><p>

  158.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  159.         file or on the server command line.

  160.        </p></dd><dt id="GUC-LOG-ROTATION-AGE"><span class="term"><code class="varname">log_rotation_age</code> (<code class="type">integer</code>)

  161.       <a id="id-1.6.6.11.3.4.6.1.3" class="indexterm"></a>

  162.       </span></dt><dd><p>

  163.         When <code class="varname">logging_collector</code> is enabled,

  164.         this parameter determines the maximum amount of time to use an

  165.         individual log file, after which a new log file will be created.

  166.         If this value is specified without units, it is taken as minutes.

  167.         The default is 24 hours.

  168.         Set to zero to disable time-based creation of new log files.

  169.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  170.         file or on the server command line.

  171.        </p></dd><dt id="GUC-LOG-ROTATION-SIZE"><span class="term"><code class="varname">log_rotation_size</code> (<code class="type">integer</code>)

  172.       <a id="id-1.6.6.11.3.4.7.1.3" class="indexterm"></a>

  173.       </span></dt><dd><p>

  174.         When <code class="varname">logging_collector</code> is enabled,

  175.         this parameter determines the maximum size of an individual log file.

  176.         After this amount of data has been emitted into a log file,

  177.         a new log file will be created.

  178.         If this value is specified without units, it is taken as kilobytes.

  179.         The default is 10 megabytes.

  180.         Set to zero to disable size-based creation of new log files.

  181.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  182.         file or on the server command line.

  183.        </p></dd><dt id="GUC-LOG-TRUNCATE-ON-ROTATION"><span class="term"><code class="varname">log_truncate_on_rotation</code> (<code class="type">boolean</code>)

  184.       <a id="id-1.6.6.11.3.4.8.1.3" class="indexterm"></a>

  185.       </span></dt><dd><p>

  186.         When <code class="varname">logging_collector</code> is enabled,

  187.         this parameter will cause <span class="productname">PostgreSQL</span> to truncate (overwrite),

  188.         rather than append to, any existing log file of the same name.

  189.         However, truncation will occur only when a new file is being opened

  190.         due to time-based rotation, not during server startup or size-based

  191.         rotation.  When off, pre-existing files will be appended to in

  192.         all cases.  For example, using this setting in combination with

  193.         a <code class="varname">log_filename</code> like <code class="literal">postgresql-%H.log</code>

  194.         would result in generating twenty-four hourly log files and then

  195.         cyclically overwriting them.

  196.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  197.         file or on the server command line.

  198.        </p><p>

  199.         Example:  To keep 7 days of logs, one log file per day named

  200.         <code class="literal">server_log.Mon</code>, <code class="literal">server_log.Tue</code>,

  201.         etc, and automatically overwrite last week's log with this week's log,

  202.         set <code class="varname">log_filename</code> to <code class="literal">server_log.%a</code>,

  203.         <code class="varname">log_truncate_on_rotation</code> to <code class="literal">on</code>, and

  204.         <code class="varname">log_rotation_age</code> to <code class="literal">1440</code>.

  205.        </p><p>

  206.         Example: To keep 24 hours of logs, one log file per hour, but

  207.         also rotate sooner if the log file size exceeds 1GB, set

  208.         <code class="varname">log_filename</code> to <code class="literal">server_log.%H%M</code>,

  209.         <code class="varname">log_truncate_on_rotation</code> to <code class="literal">on</code>,

  210.         <code class="varname">log_rotation_age</code> to <code class="literal">60</code>, and

  211.         <code class="varname">log_rotation_size</code> to <code class="literal">1000000</code>.

  212.         Including <code class="literal">%M</code> in <code class="varname">log_filename</code> allows

  213.         any size-driven rotations that might occur to select a file name

  214.         different from the hour's initial file name.

  215.        </p></dd><dt id="GUC-SYSLOG-FACILITY"><span class="term"><code class="varname">syslog_facility</code> (<code class="type">enum</code>)

  216.       <a id="id-1.6.6.11.3.4.9.1.3" class="indexterm"></a>

  217.       </span></dt><dd><p>

  218.         When logging to <span class="application">syslog</span> is enabled, this parameter

  219.         determines the <span class="application">syslog</span>

  220.         <span class="quote">“<span class="quote">facility</span>”</span> to be used.  You can choose

  221.         from <code class="literal">LOCAL0</code>, <code class="literal">LOCAL1</code>,

  222.         <code class="literal">LOCAL2</code>, <code class="literal">LOCAL3</code>, <code class="literal">LOCAL4</code>,

  223.         <code class="literal">LOCAL5</code>, <code class="literal">LOCAL6</code>, <code class="literal">LOCAL7</code>;

  224.         the default is <code class="literal">LOCAL0</code>. See also the

  225.         documentation of your system's

  226.         <span class="application">syslog</span> daemon.

  227.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  228.         file or on the server command line.

  229.        </p></dd><dt id="GUC-SYSLOG-IDENT"><span class="term"><code class="varname">syslog_ident</code> (<code class="type">string</code>)

  230.       <a id="id-1.6.6.11.3.4.10.1.3" class="indexterm"></a>

  231.       </span></dt><dd><p>

  232.          When logging to <span class="application">syslog</span> is enabled, this parameter

  233.          determines the program name used to identify

  234.          <span class="productname">PostgreSQL</span> messages in

  235.          <span class="application">syslog</span> logs. The default is

  236.          <code class="literal">postgres</code>.

  237.          This parameter can only be set in the <code class="filename">postgresql.conf</code>

  238.          file or on the server command line.

  239.         </p></dd><dt id="GUC-SYSLOG-SEQUENCE-NUMBERS"><span class="term"><code class="varname">syslog_sequence_numbers</code> (<code class="type">boolean</code>)

  240.         <a id="id-1.6.6.11.3.4.11.1.3" class="indexterm"></a>

  241.        </span></dt><dd><p>

  242.          When logging to <span class="application">syslog</span> and this is on (the

  243.          default), then each message will be prefixed by an increasing

  244.          sequence number (such as <code class="literal">[2]</code>).  This circumvents

  245.          the <span class="quote">“<span class="quote">--- last message repeated N times ---</span>”</span> suppression

  246.          that many syslog implementations perform by default.  In more modern

  247.          syslog implementations, repeated message suppression can be configured

  248.          (for example, <code class="literal">$RepeatedMsgReduction</code>

  249.          in <span class="productname">rsyslog</span>), so this might not be

  250.          necessary.  Also, you could turn this off if you actually want to

  251.          suppress repeated messages.

  252.         </p><p>

  253.          This parameter can only be set in the <code class="filename">postgresql.conf</code>

  254.          file or on the server command line.

  255.         </p></dd><dt id="GUC-SYSLOG-SPLIT-MESSAGES"><span class="term"><code class="varname">syslog_split_messages</code> (<code class="type">boolean</code>)

  256.       <a id="id-1.6.6.11.3.4.12.1.3" class="indexterm"></a>

  257.       </span></dt><dd><p>

  258.         When logging to <span class="application">syslog</span> is enabled, this parameter

  259.         determines how messages are delivered to syslog.  When on (the

  260.         default), messages are split by lines, and long lines are split so

  261.         that they will fit into 1024 bytes, which is a typical size limit for

  262.         traditional syslog implementations.  When off, PostgreSQL server log

  263.         messages are delivered to the syslog service as is, and it is up to

  264.         the syslog service to cope with the potentially bulky messages.

  265.        </p><p>

  266.         If syslog is ultimately logging to a text file, then the effect will

  267.         be the same either way, and it is best to leave the setting on, since

  268.         most syslog implementations either cannot handle large messages or

  269.         would need to be specially configured to handle them.  But if syslog

  270.         is ultimately writing into some other medium, it might be necessary or

  271.         more useful to keep messages logically together.

  272.        </p><p>

  273.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  274.         file or on the server command line.

  275.        </p></dd><dt id="GUC-EVENT-SOURCE"><span class="term"><code class="varname">event_source</code> (<code class="type">string</code>)

  276.       <a id="id-1.6.6.11.3.4.13.1.3" class="indexterm"></a>

  277.       </span></dt><dd><p>

  278.         When logging to <span class="application">event log</span> is enabled, this parameter

  279.         determines the program name used to identify

  280.         <span class="productname">PostgreSQL</span> messages in

  281.         the log. The default is <code class="literal">PostgreSQL</code>.

  282.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  283.         file or on the server command line.

  284.        </p></dd></dl></div></div><div class="sect2" id="RUNTIME-CONFIG-LOGGING-WHEN"><div class="titlepage"><div><div><h3 class="title">19.8.2. When to Log</h3></div></div></div><div class="variablelist"><dl class="variablelist"><dt id="GUC-LOG-MIN-MESSAGES"><span class="term"><code class="varname">log_min_messages</code> (<code class="type">enum</code>)

  285.       <a id="id-1.6.6.11.4.2.1.1.3" class="indexterm"></a>

  286.       </span></dt><dd><p>

  287.         Controls which <a class="link" href="runtime-config-logging.html#RUNTIME-CONFIG-SEVERITY-LEVELS" title="Table 19.1. Message Severity Levels">message

  288.         levels</a> are written to the server log.

  289.         Valid values are <code class="literal">DEBUG5</code>, <code class="literal">DEBUG4</code>,

  290.         <code class="literal">DEBUG3</code>, <code class="literal">DEBUG2</code>, <code class="literal">DEBUG1</code>,

  291.         <code class="literal">INFO</code>, <code class="literal">NOTICE</code>, <code class="literal">WARNING</code>,

  292.         <code class="literal">ERROR</code>, <code class="literal">LOG</code>, <code class="literal">FATAL</code>, and

  293.         <code class="literal">PANIC</code>.  Each level includes all the levels that

  294.         follow it.  The later the level, the fewer messages are sent

  295.         to the log.  The default is <code class="literal">WARNING</code>.  Note that

  296.         <code class="literal">LOG</code> has a different rank here than in

  297.         <a class="xref" href="runtime-config-client.html#GUC-CLIENT-MIN-MESSAGES">client_min_messages</a>.

  298.         Only superusers can change this setting.

  299.        </p></dd><dt id="GUC-LOG-MIN-ERROR-STATEMENT"><span class="term"><code class="varname">log_min_error_statement</code> (<code class="type">enum</code>)

  300.       <a id="id-1.6.6.11.4.2.2.1.3" class="indexterm"></a>

  301.       </span></dt><dd><p>

  302.         Controls which SQL statements that cause an error

  303.         condition are recorded in the server log.  The current

  304.         SQL statement is included in the log entry for any message of

  305.         the specified

  306.         <a class="link" href="runtime-config-logging.html#RUNTIME-CONFIG-SEVERITY-LEVELS" title="Table 19.1. Message Severity Levels">severity</a>

  307.         or higher.

  308.         Valid values are <code class="literal">DEBUG5</code>,

  309.         <code class="literal">DEBUG4</code>, <code class="literal">DEBUG3</code>,

  310.         <code class="literal">DEBUG2</code>, <code class="literal">DEBUG1</code>,

  311.         <code class="literal">INFO</code>, <code class="literal">NOTICE</code>,

  312.         <code class="literal">WARNING</code>, <code class="literal">ERROR</code>,

  313.         <code class="literal">LOG</code>,

  314.         <code class="literal">FATAL</code>, and <code class="literal">PANIC</code>.

  315.         The default is <code class="literal">ERROR</code>, which means statements

  316.         causing errors, log messages, fatal errors, or panics will be logged.

  317.         To effectively turn off logging of failing statements,

  318.         set this parameter to <code class="literal">PANIC</code>.

  319.         Only superusers can change this setting.

  320.        </p></dd><dt id="GUC-LOG-MIN-DURATION-STATEMENT"><span class="term"><code class="varname">log_min_duration_statement</code> (<code class="type">integer</code>)

  321.       <a id="id-1.6.6.11.4.2.3.1.3" class="indexterm"></a>

  322.       </span></dt><dd><p>

  323.          Causes the duration of each completed statement to be logged

  324.          if the statement ran for at least the specified amount of time.

  325.          If this value is specified without units, it is taken as milliseconds.

  326.          Setting this to zero prints all statement durations.

  327.          Minus-one (the default) disables logging statement durations.

  328.          For example, if you set it to <code class="literal">250ms</code>

  329.          then all SQL statements that run 250ms or longer will be

  330.          logged.  Enabling this parameter can be helpful in tracking down

  331.          unoptimized queries in your applications.

  332.          Only superusers can change this setting.

  333.         </p><p>

  334.          For clients using extended query protocol, durations of the Parse,

  335.          Bind, and Execute steps are logged independently.

  336.         </p><div class="note"><h3 class="title">Note</h3><p>

  337.          When using this option together with

  338.          <a class="xref" href="runtime-config-logging.html#GUC-LOG-STATEMENT">log_statement</a>,

  339.          the text of statements that are logged because of

  340.          <code class="varname">log_statement</code> will not be repeated in the

  341.          duration log message.

  342.          If you are not using <span class="application">syslog</span>, it is recommended

  343.          that you log the PID or session ID using

  344.          <a class="xref" href="runtime-config-logging.html#GUC-LOG-LINE-PREFIX">log_line_prefix</a>

  345.          so that you can link the statement message to the later

  346.          duration message using the process ID or session ID.

  347.         </p></div></dd><dt id="GUC-LOG-TRANSACTION-SAMPLE-RATE"><span class="term"><code class="varname">log_transaction_sample_rate</code> (<code class="type">real</code>)

  348.       <a id="id-1.6.6.11.4.2.4.1.3" class="indexterm"></a>

  349.       </span></dt><dd><p>

  350.          Set the fraction of transactions whose statements are all logged,

  351.          in addition to statements logged for other reasons.  It applies to

  352.          each new transaction regardless of its statements' durations.

  353.          The default is <code class="literal">0</code>, meaning not to log statements

  354.          from any additional transaction.  Setting this to <code class="literal">1</code>

  355.          logs all statements for all transactions.

  356.          <code class="varname">log_transaction_sample_rate</code> is helpful to track a

  357.          sample of transaction.

  358.          Only superusers can change this setting.

  359.         </p><div class="note"><h3 class="title">Note</h3><p>

  360.          Like all statement-logging options, this option can add significant

  361.          overhead.

  362.         </p></div></dd></dl></div><p>

  363.      <a class="xref" href="runtime-config-logging.html#RUNTIME-CONFIG-SEVERITY-LEVELS" title="Table 19.1. Message Severity Levels">Table 19.1</a> explains the message

  364.      severity levels used by <span class="productname">PostgreSQL</span>.  If logging output

  365.      is sent to <span class="systemitem">syslog</span> or Windows'

  366.      <span class="systemitem">eventlog</span>, the severity levels are translated

  367.      as shown in the table.

  368.     </p><div class="table" id="RUNTIME-CONFIG-SEVERITY-LEVELS"><p class="title"><strong>Table 19.1. Message Severity Levels</strong></p><div class="table-contents"><table class="table" summary="Message Severity Levels" border="1"><colgroup><col /><col /><col /><col /></colgroup><thead><tr><th>Severity</th><th>Usage</th><th><span class="systemitem">syslog</span></th><th><span class="systemitem">eventlog</span></th></tr></thead><tbody><tr><td><code class="literal">DEBUG1..DEBUG5</code></td><td>Provides successively-more-detailed information for use by

  369.          developers.</td><td><code class="literal">DEBUG</code></td><td><code class="literal">INFORMATION</code></td></tr><tr><td><code class="literal">INFO</code></td><td>Provides information implicitly requested by the user,

  370.          e.g., output from <code class="command">VACUUM VERBOSE</code>.</td><td><code class="literal">INFO</code></td><td><code class="literal">INFORMATION</code></td></tr><tr><td><code class="literal">NOTICE</code></td><td>Provides information that might be helpful to users, e.g.,

  371.          notice of truncation of long identifiers.</td><td><code class="literal">NOTICE</code></td><td><code class="literal">INFORMATION</code></td></tr><tr><td><code class="literal">WARNING</code></td><td>Provides warnings of likely problems, e.g., <code class="command">COMMIT</code>

  372.          outside a transaction block.</td><td><code class="literal">NOTICE</code></td><td><code class="literal">WARNING</code></td></tr><tr><td><code class="literal">ERROR</code></td><td>Reports an error that caused the current command to

  373.          abort.</td><td><code class="literal">WARNING</code></td><td><code class="literal">ERROR</code></td></tr><tr><td><code class="literal">LOG</code></td><td>Reports information of interest to administrators, e.g.,

  374.          checkpoint activity.</td><td><code class="literal">INFO</code></td><td><code class="literal">INFORMATION</code></td></tr><tr><td><code class="literal">FATAL</code></td><td>Reports an error that caused the current session to

  375.          abort.</td><td><code class="literal">ERR</code></td><td><code class="literal">ERROR</code></td></tr><tr><td><code class="literal">PANIC</code></td><td>Reports an error that caused all database sessions to abort.</td><td><code class="literal">CRIT</code></td><td><code class="literal">ERROR</code></td></tr></tbody></table></div></div><br class="table-break" /></div><div class="sect2" id="RUNTIME-CONFIG-LOGGING-WHAT"><div class="titlepage"><div><div><h3 class="title">19.8.3. What to Log</h3></div></div></div><div class="variablelist"><dl class="variablelist"><dt id="GUC-APPLICATION-NAME"><span class="term"><code class="varname">application_name</code> (<code class="type">string</code>)

  376.       <a id="id-1.6.6.11.5.2.1.1.3" class="indexterm"></a>

  377.       </span></dt><dd><p>

  378.         The <code class="varname">application_name</code> can be any string of less than

  379.         <code class="symbol">NAMEDATALEN</code> characters (64 characters in a standard build).

  380.         It is typically set by an application upon connection to the server.

  381.         The name will be displayed in the <code class="structname">pg_stat_activity</code> view

  382.         and included in CSV log entries.  It can also be included in regular

  383.         log entries via the <a class="xref" href="runtime-config-logging.html#GUC-LOG-LINE-PREFIX">log_line_prefix</a> parameter.

  384.         Only printable ASCII characters may be used in the

  385.         <code class="varname">application_name</code> value. Other characters will be

  386.         replaced with question marks (<code class="literal">?</code>).

  387.        </p></dd><dt><span class="term"><code class="varname">debug_print_parse</code> (<code class="type">boolean</code>)

  388.       <a id="id-1.6.6.11.5.2.2.1.3" class="indexterm"></a>

  389.       <br /></span><span class="term"><code class="varname">debug_print_rewritten</code> (<code class="type">boolean</code>)

  390.       <a id="id-1.6.6.11.5.2.2.2.3" class="indexterm"></a>

  391.       <br /></span><span class="term"><code class="varname">debug_print_plan</code> (<code class="type">boolean</code>)

  392.       <a id="id-1.6.6.11.5.2.2.3.3" class="indexterm"></a>

  393.       </span></dt><dd><p>

  394.         These parameters enable various debugging output to be emitted.

  395.         When set, they print the resulting parse tree, the query rewriter

  396.         output, or the execution plan for each executed query.

  397.         These messages are emitted at <code class="literal">LOG</code> message level, so by

  398.         default they will appear in the server log but will not be sent to the

  399.         client.  You can change that by adjusting

  400.         <a class="xref" href="runtime-config-client.html#GUC-CLIENT-MIN-MESSAGES">client_min_messages</a> and/or

  401.         <a class="xref" href="runtime-config-logging.html#GUC-LOG-MIN-MESSAGES">log_min_messages</a>.

  402.         These parameters are off by default.

  403.        </p></dd><dt><span class="term"><code class="varname">debug_pretty_print</code> (<code class="type">boolean</code>)

  404.       <a id="id-1.6.6.11.5.2.3.1.3" class="indexterm"></a>

  405.       </span></dt><dd><p>

  406.         When set, <code class="varname">debug_pretty_print</code> indents the messages

  407.         produced by <code class="varname">debug_print_parse</code>,

  408.         <code class="varname">debug_print_rewritten</code>, or

  409.         <code class="varname">debug_print_plan</code>.  This results in more readable

  410.         but much longer output than the <span class="quote">“<span class="quote">compact</span>”</span> format used when

  411.         it is off.  It is on by default.

  412.        </p></dd><dt id="GUC-LOG-CHECKPOINTS"><span class="term"><code class="varname">log_checkpoints</code> (<code class="type">boolean</code>)

  413.       <a id="id-1.6.6.11.5.2.4.1.3" class="indexterm"></a>

  414.       </span></dt><dd><p>

  415.         Causes checkpoints and restartpoints to be logged in the server log.

  416.         Some statistics are included in the log messages, including the number

  417.         of buffers written and the time spent writing them.

  418.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  419.         file or on the server command line. The default is off.

  420.        </p></dd><dt id="GUC-LOG-CONNECTIONS"><span class="term"><code class="varname">log_connections</code> (<code class="type">boolean</code>)

  421.       <a id="id-1.6.6.11.5.2.5.1.3" class="indexterm"></a>

  422.       </span></dt><dd><p>

  423.         Causes each attempted connection to the server to be logged,

  424.         as well as successful completion of client authentication.

  425.         Only superusers can change this parameter at session start,

  426.         and it cannot be changed at all within a session.

  427.         The default is <code class="literal">off</code>.

  428.        </p><div class="note"><h3 class="title">Note</h3><p>

  429.          Some client programs, like <span class="application">psql</span>, attempt

  430.          to connect twice while determining if a password is required, so

  431.          duplicate <span class="quote">“<span class="quote">connection received</span>”</span> messages do not

  432.          necessarily indicate a problem.

  433.         </p></div></dd><dt id="GUC-LOG-DISCONNECTIONS"><span class="term"><code class="varname">log_disconnections</code> (<code class="type">boolean</code>)

  434.       <a id="id-1.6.6.11.5.2.6.1.3" class="indexterm"></a>

  435.       </span></dt><dd><p>

  436.         Causes session terminations to be logged.  The log output

  437.         provides information similar to <code class="varname">log_connections</code>,

  438.         plus the duration of the session.

  439.         Only superusers can change this parameter at session start,

  440.         and it cannot be changed at all within a session.

  441.         The default is <code class="literal">off</code>.

  442.        </p></dd><dt id="GUC-LOG-DURATION"><span class="term"><code class="varname">log_duration</code> (<code class="type">boolean</code>)

  443.       <a id="id-1.6.6.11.5.2.7.1.3" class="indexterm"></a>

  444.       </span></dt><dd><p>

  445.         Causes the duration of every completed statement to be logged.

  446.         The default is <code class="literal">off</code>.

  447.         Only superusers can change this setting.

  448.        </p><p>

  449.         For clients using extended query protocol, durations of the Parse,

  450.         Bind, and Execute steps are logged independently.

  451.        </p><div class="note"><h3 class="title">Note</h3><p>

  452.          The difference between enabling <code class="varname">log_duration</code> and setting

  453.          <a class="xref" href="runtime-config-logging.html#GUC-LOG-MIN-DURATION-STATEMENT">log_min_duration_statement</a> to zero is that

  454.          exceeding <code class="varname">log_min_duration_statement</code> forces the text of

  455.          the query to be logged, but this option doesn't.  Thus, if

  456.          <code class="varname">log_duration</code> is <code class="literal">on</code> and

  457.          <code class="varname">log_min_duration_statement</code> has a positive value, all

  458.          durations are logged but the query text is included only for

  459.          statements exceeding the threshold.  This behavior can be useful for

  460.          gathering statistics in high-load installations.

  461.         </p></div></dd><dt id="GUC-LOG-ERROR-VERBOSITY"><span class="term"><code class="varname">log_error_verbosity</code> (<code class="type">enum</code>)

  462.       <a id="id-1.6.6.11.5.2.8.1.3" class="indexterm"></a>

  463.       </span></dt><dd><p>

  464.         Controls the amount of detail written in the server log for each

  465.         message that is logged.  Valid values are <code class="literal">TERSE</code>,

  466.         <code class="literal">DEFAULT</code>, and <code class="literal">VERBOSE</code>, each adding more

  467.         fields to displayed messages.  <code class="literal">TERSE</code> excludes

  468.         the logging of <code class="literal">DETAIL</code>, <code class="literal">HINT</code>,

  469.         <code class="literal">QUERY</code>, and <code class="literal">CONTEXT</code> error information.

  470.         <code class="literal">VERBOSE</code> output includes the <code class="symbol">SQLSTATE</code> error

  471.         code (see also <a class="xref" href="errcodes-appendix.html" title="Appendix A. PostgreSQL Error Codes">Appendix A</a>) and the source code file name, function name,

  472.         and line number that generated the error.

  473.         Only superusers can change this setting.

  474.        </p></dd><dt id="GUC-LOG-HOSTNAME"><span class="term"><code class="varname">log_hostname</code> (<code class="type">boolean</code>)

  475.       <a id="id-1.6.6.11.5.2.9.1.3" class="indexterm"></a>

  476.       </span></dt><dd><p>

  477.         By default, connection log messages only show the IP address of the

  478.         connecting host. Turning this parameter on causes logging of the

  479.         host name as well.  Note that depending on your host name resolution

  480.         setup this might impose a non-negligible performance penalty.

  481.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  482.         file or on the server command line.

  483.        </p></dd><dt id="GUC-LOG-LINE-PREFIX"><span class="term"><code class="varname">log_line_prefix</code> (<code class="type">string</code>)

  484.       <a id="id-1.6.6.11.5.2.10.1.3" class="indexterm"></a>

  485.       </span></dt><dd><p>

  486.          This is a <code class="function">printf</code>-style string that is output at the

  487.          beginning of each log line.

  488.          <code class="literal">%</code> characters begin <span class="quote">“<span class="quote">escape sequences</span>”</span>

  489.          that are replaced with status information as outlined below.

  490.          Unrecognized escapes are ignored. Other

  491.          characters are copied straight to the log line. Some escapes are

  492.          only recognized by session processes, and will be treated as empty by

  493.          background processes such as the main server process. Status

  494.          information may be aligned either left or right by specifying a

  495.          numeric literal after the % and before the option. A negative

  496.          value will cause the status information to be padded on the

  497.          right with spaces to give it a minimum width, whereas a positive

  498.          value will pad on the left. Padding can be useful to aid human

  499.          readability in log files.

  500.          This parameter can only be set in the <code class="filename">postgresql.conf</code>

  501.          file or on the server command line. The default is

  502.          <code class="literal">'%m [%p] '</code> which logs a time stamp and the process ID.

  503. 

  504.          </p><div class="informaltable"><table class="informaltable" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Escape</th><th>Effect</th><th>Session only</th></tr></thead><tbody><tr><td><code class="literal">%a</code></td><td>Application name</td><td>yes</td></tr><tr><td><code class="literal">%u</code></td><td>User name</td><td>yes</td></tr><tr><td><code class="literal">%d</code></td><td>Database name</td><td>yes</td></tr><tr><td><code class="literal">%r</code></td><td>Remote host name or IP address, and remote port</td><td>yes</td></tr><tr><td><code class="literal">%h</code></td><td>Remote host name or IP address</td><td>yes</td></tr><tr><td><code class="literal">%p</code></td><td>Process ID</td><td>no</td></tr><tr><td><code class="literal">%t</code></td><td>Time stamp without milliseconds</td><td>no</td></tr><tr><td><code class="literal">%m</code></td><td>Time stamp with milliseconds</td><td>no</td></tr><tr><td><code class="literal">%n</code></td><td>Time stamp with milliseconds (as a Unix epoch)</td><td>no</td></tr><tr><td><code class="literal">%i</code></td><td>Command tag: type of session's current command</td><td>yes</td></tr><tr><td><code class="literal">%e</code></td><td>SQLSTATE error code</td><td>no</td></tr><tr><td><code class="literal">%c</code></td><td>Session ID: see below</td><td>no</td></tr><tr><td><code class="literal">%l</code></td><td>Number of the log line for each session or process, starting at 1</td><td>no</td></tr><tr><td><code class="literal">%s</code></td><td>Process start time stamp</td><td>no</td></tr><tr><td><code class="literal">%v</code></td><td>Virtual transaction ID (backendID/localXID)</td><td>no</td></tr><tr><td><code class="literal">%x</code></td><td>Transaction ID (0 if none is assigned)</td><td>no</td></tr><tr><td><code class="literal">%q</code></td><td>Produces no output, but tells non-session

  505.              processes to stop at this point in the string; ignored by

  506.              session processes</td><td>no</td></tr><tr><td><code class="literal">%%</code></td><td>Literal <code class="literal">%</code></td><td>no</td></tr></tbody></table></div><p>

  507. 

  508.          The <code class="literal">%c</code> escape prints a quasi-unique session identifier,

  509.          consisting of two 4-byte hexadecimal numbers (without leading zeros)

  510.          separated by a dot.  The numbers are the process start time and the

  511.          process ID, so <code class="literal">%c</code> can also be used as a space saving way

  512.          of printing those items.  For example, to generate the session

  513.          identifier from <code class="literal">pg_stat_activity</code>, use this query:

  514. </p><pre class="programlisting">

  515. SELECT to_hex(trunc(EXTRACT(EPOCH FROM backend_start))::integer) || '.' ||

  516.        to_hex(pid)

  517. FROM pg_stat_activity;

  518. </pre><p>

  519. 

  520.        </p><div class="tip"><h3 class="title">Tip</h3><p>

  521.          If you set a nonempty value for <code class="varname">log_line_prefix</code>,

  522.          you should usually make its last character be a space, to provide

  523.          visual separation from the rest of the log line.  A punctuation

  524.          character can be used too.

  525.         </p></div><div class="tip"><h3 class="title">Tip</h3><p>

  526.          <span class="application">Syslog</span> produces its own

  527.          time stamp and process ID information, so you probably do not want to

  528.          include those escapes if you are logging to <span class="application">syslog</span>.

  529.         </p></div><div class="tip"><h3 class="title">Tip</h3><p>

  530.          The <code class="literal">%q</code> escape is useful when including information that is

  531.          only available in session (backend) context like user or database

  532.          name.  For example:

  533. </p><pre class="programlisting">

  534. log_line_prefix = '%m [%p] %q%u@%d/%a '

  535. </pre><p>

  536.         </p></div></dd><dt id="GUC-LOG-LOCK-WAITS"><span class="term"><code class="varname">log_lock_waits</code> (<code class="type">boolean</code>)

  537.       <a id="id-1.6.6.11.5.2.11.1.3" class="indexterm"></a>

  538.       </span></dt><dd><p>

  539.         Controls whether a log message is produced when a session waits

  540.         longer than <a class="xref" href="runtime-config-locks.html#GUC-DEADLOCK-TIMEOUT">deadlock_timeout</a> to acquire a

  541.         lock.  This is useful in determining if lock waits are causing

  542.         poor performance.  The default is <code class="literal">off</code>.

  543.         Only superusers can change this setting.

  544.        </p></dd><dt id="GUC-LOG-STATEMENT"><span class="term"><code class="varname">log_statement</code> (<code class="type">enum</code>)

  545.       <a id="id-1.6.6.11.5.2.12.1.3" class="indexterm"></a>

  546.       </span></dt><dd><p>

  547.         Controls which SQL statements are logged. Valid values are

  548.         <code class="literal">none</code> (off), <code class="literal">ddl</code>, <code class="literal">mod</code>, and

  549.         <code class="literal">all</code> (all statements). <code class="literal">ddl</code> logs all data definition

  550.         statements, such as <code class="command">CREATE</code>, <code class="command">ALTER</code>, and

  551.         <code class="command">DROP</code> statements. <code class="literal">mod</code> logs all

  552.         <code class="literal">ddl</code> statements, plus data-modifying statements

  553.         such as <code class="command">INSERT</code>,

  554.         <code class="command">UPDATE</code>, <code class="command">DELETE</code>, <code class="command">TRUNCATE</code>,

  555.         and <code class="command">COPY FROM</code>.

  556.         <code class="command">PREPARE</code>, <code class="command">EXECUTE</code>, and

  557.         <code class="command">EXPLAIN ANALYZE</code> statements are also logged if their

  558.         contained command is of an appropriate type.  For clients using

  559.         extended query protocol, logging occurs when an Execute message

  560.         is received, and values of the Bind parameters are included

  561.         (with any embedded single-quote marks doubled).

  562.        </p><p>

  563.         The default is <code class="literal">none</code>. Only superusers can change this

  564.         setting.

  565.        </p><div class="note"><h3 class="title">Note</h3><p>

  566.          Statements that contain simple syntax errors are not logged

  567.          even by the <code class="varname">log_statement</code> = <code class="literal">all</code> setting,

  568.          because the log message is emitted only after basic parsing has

  569.          been done to determine the statement type.  In the case of extended

  570.          query protocol, this setting likewise does not log statements that

  571.          fail before the Execute phase (i.e., during parse analysis or

  572.          planning).  Set <code class="varname">log_min_error_statement</code> to

  573.          <code class="literal">ERROR</code> (or lower) to log such statements.

  574.         </p></div></dd><dt id="GUC-LOG-REPLICATION-COMMANDS"><span class="term"><code class="varname">log_replication_commands</code> (<code class="type">boolean</code>)

  575.       <a id="id-1.6.6.11.5.2.13.1.3" class="indexterm"></a>

  576.       </span></dt><dd><p>

  577.         Causes each replication command to be logged in the server log.

  578.         See <a class="xref" href="protocol-replication.html" title="52.4. Streaming Replication Protocol">Section 52.4</a> for more information about

  579.         replication command. The default value is <code class="literal">off</code>.

  580.         Only superusers can change this setting.

  581.        </p></dd><dt id="GUC-LOG-TEMP-FILES"><span class="term"><code class="varname">log_temp_files</code> (<code class="type">integer</code>)

  582.       <a id="id-1.6.6.11.5.2.14.1.3" class="indexterm"></a>

  583.       </span></dt><dd><p>

  584.         Controls logging of temporary file names and sizes.

  585.         Temporary files can be

  586.         created for sorts, hashes, and temporary query results.

  587.         If enabled by this setting, a log entry is emitted for each

  588.         temporary file when it is deleted.

  589.         A value of zero logs all temporary file information, while positive

  590.         values log only files whose size is greater than or equal to

  591.         the specified amount of data.

  592.         If this value is specified without units, it is taken as kilobytes.

  593.         The default setting is -1, which disables such logging.

  594.         Only superusers can change this setting.

  595.        </p></dd><dt id="GUC-LOG-TIMEZONE"><span class="term"><code class="varname">log_timezone</code> (<code class="type">string</code>)

  596.       <a id="id-1.6.6.11.5.2.15.1.3" class="indexterm"></a>

  597.       </span></dt><dd><p>

  598.         Sets the time zone used for timestamps written in the server log.

  599.         Unlike <a class="xref" href="runtime-config-client.html#GUC-TIMEZONE">TimeZone</a>, this value is cluster-wide,

  600.         so that all sessions will report timestamps consistently.

  601.         The built-in default is <code class="literal">GMT</code>, but that is typically

  602.         overridden in <code class="filename">postgresql.conf</code>; <span class="application">initdb</span>

  603.         will install a setting there corresponding to its system environment.

  604.         See <a class="xref" href="datatype-datetime.html#DATATYPE-TIMEZONES" title="8.5.3. Time Zones">Section 8.5.3</a> for more information.

  605.         This parameter can only be set in the <code class="filename">postgresql.conf</code>

  606.         file or on the server command line.

  607.        </p></dd></dl></div></div><div class="sect2" id="RUNTIME-CONFIG-LOGGING-CSVLOG"><div class="titlepage"><div><div><h3 class="title">19.8.4. Using CSV-Format Log Output</h3></div></div></div><p>

  608.         Including <code class="literal">csvlog</code> in the <code class="varname">log_destination</code> list

  609.         provides a convenient way to import log files into a database table.

  610.         This option emits log lines in comma-separated-values

  611.         (<acronym class="acronym">CSV</acronym>) format,

  612.         with these columns:

  613.         time stamp with milliseconds,

  614.         user name,

  615.         database name,

  616.         process ID,

  617.         client host:port number,

  618.         session ID,

  619.         per-session line number,

  620.         command tag,

  621.         session start time,

  622.         virtual transaction ID,

  623.         regular transaction ID,

  624.         error severity,

  625.         SQLSTATE code,

  626.         error message,

  627.         error message detail,

  628.         hint,

  629.         internal query that led to the error (if any),

  630.         character count of the error position therein,

  631.         error context,

  632.         user query that led to the error (if any and enabled by

  633.         <code class="varname">log_min_error_statement</code>),

  634.         character count of the error position therein,

  635.         location of the error in the PostgreSQL source code

  636.         (if <code class="varname">log_error_verbosity</code> is set to <code class="literal">verbose</code>),

  637.         and application name.

  638.         Here is a sample table definition for storing CSV-format log output:

  639. 

  640. </p><pre class="programlisting">

  641. CREATE TABLE postgres_log

  642. (

  643.   log_time timestamp(3) with time zone,

  644.   user_name text,

  645.   database_name text,

  646.   process_id integer,

  647.   connection_from text,

  648.   session_id text,

  649.   session_line_num bigint,

  650.   command_tag text,

  651.   session_start_time timestamp with time zone,

  652.   virtual_transaction_id text,

  653.   transaction_id bigint,

  654.   error_severity text,

  655.   sql_state_code text,

  656.   message text,

  657.   detail text,

  658.   hint text,

  659.   internal_query text,

  660.   internal_query_pos integer,

  661.   context text,

  662.   query text,

  663.   query_pos integer,

  664.   location text,

  665.   application_name text,

  666.   PRIMARY KEY (session_id, session_line_num)

  667. );

  668. </pre><p>

  669.        </p><p>

  670.         To import a log file into this table, use the <code class="command">COPY FROM</code>

  671.         command:

  672. 

  673. </p><pre class="programlisting">

  674. COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;

  675. </pre><p>

  676.        </p><p>

  677.        There are a few things you need to do to simplify importing CSV log

  678.        files:

  679. 

  680.        </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>

  681.             Set <code class="varname">log_filename</code> and

  682.             <code class="varname">log_rotation_age</code> to provide a consistent,

  683.             predictable naming scheme for your log files.  This lets you

  684.             predict what the file name will be and know when an individual log

  685.             file is complete and therefore ready to be imported.

  686.          </p></li><li class="listitem"><p>

  687.             Set <code class="varname">log_rotation_size</code> to 0 to disable

  688.             size-based log rotation, as it makes the log file name difficult

  689.             to predict.

  690.            </p></li><li class="listitem"><p>

  691.            Set <code class="varname">log_truncate_on_rotation</code> to <code class="literal">on</code> so

  692.            that old log data isn't mixed with the new in the same file.

  693.           </p></li><li class="listitem"><p>

  694.            The table definition above includes a primary key specification.

  695.            This is useful to protect against accidentally importing the same

  696.            information twice.  The <code class="command">COPY</code> command commits all of the

  697.            data it imports at one time, so any error will cause the entire

  698.            import to fail.  If you import a partial log file and later import

  699.            the file again when it is complete, the primary key violation will

  700.            cause the import to fail.  Wait until the log is complete and

  701.            closed before importing.  This procedure will also protect against

  702.            accidentally importing a partial line that hasn't been completely

  703.            written, which would also cause <code class="command">COPY</code> to fail.

  704.           </p></li></ol></div><p>

  705.       </p></div><div class="sect2" id="id-1.6.6.11.7"><div class="titlepage"><div><div><h3 class="title">19.8.5. Process Title</h3></div></div></div><p>

  706.      These settings control how process titles of server processes are

  707.      modified.  Process titles are typically viewed using programs like

  708.      <span class="application">ps</span> or, on Windows, <span class="application">Process Explorer</span>.

  709.      See <a class="xref" href="monitoring-ps.html" title="27.1. Standard Unix Tools">Section 27.1</a> for details.

  710.     </p><div class="variablelist"><dl class="variablelist"><dt id="GUC-CLUSTER-NAME"><span class="term"><code class="varname">cluster_name</code> (<code class="type">string</code>)

  711.       <a id="id-1.6.6.11.7.3.1.1.3" class="indexterm"></a>

  712.       </span></dt><dd><p>

  713.         Sets a name that identifies this database cluster (instance) for

  714.         various purposes.  The cluster name appears in the process title for

  715.         all server processes in this cluster.  Moreover, it is the default

  716.         application name for a standby connection (see <a class="xref" href="runtime-config-replication.html#GUC-SYNCHRONOUS-STANDBY-NAMES">synchronous_standby_names</a>.)

  717.        </p><p>

  718.         The name can be any string of less

  719.         than <code class="symbol">NAMEDATALEN</code> characters (64 characters in a standard

  720.         build). Only printable ASCII characters may be used in the

  721.         <code class="varname">cluster_name</code> value. Other characters will be

  722.         replaced with question marks (<code class="literal">?</code>).  No name is shown

  723.         if this parameter is set to the empty string <code class="literal">''</code> (which is

  724.         the default). This parameter can only be set at server start.

  725.        </p></dd><dt id="GUC-UPDATE-PROCESS-TITLE"><span class="term"><code class="varname">update_process_title</code> (<code class="type">boolean</code>)

  726.       <a id="id-1.6.6.11.7.3.2.1.3" class="indexterm"></a>

  727.       </span></dt><dd><p>

  728.         Enables updating of the process title every time a new SQL command

  729.         is received by the server.

  730.         This setting defaults to <code class="literal">on</code> on most platforms, but it

  731.         defaults to <code class="literal">off</code> on Windows due to that platform's larger

  732.         overhead for updating the process title.

  733.         Only superusers can change this setting.

  734.        </p></dd></dl></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="runtime-config-query.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="runtime-config.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="runtime-config-statistics.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">19.7. Query Planning </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 19.9. Run-time Statistics</td></tr></table></div></body></html>
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