|
- /*-------------------------------------------------------------------------
- *
- * plannodes.h
- * definitions for query plan nodes
- *
- *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * src/include/nodes/plannodes.h
- *
- *-------------------------------------------------------------------------
- */
- #ifndef PLANNODES_H
- #define PLANNODES_H
-
- #include "access/sdir.h"
- #include "access/stratnum.h"
- #include "lib/stringinfo.h"
- #include "nodes/bitmapset.h"
- #include "nodes/lockoptions.h"
- #include "nodes/primnodes.h"
-
-
- /* ----------------------------------------------------------------
- * node definitions
- * ----------------------------------------------------------------
- */
-
- /* ----------------
- * PlannedStmt node
- *
- * The output of the planner is a Plan tree headed by a PlannedStmt node.
- * PlannedStmt holds the "one time" information needed by the executor.
- *
- * For simplicity in APIs, we also wrap utility statements in PlannedStmt
- * nodes; in such cases, commandType == CMD_UTILITY, the statement itself
- * is in the utilityStmt field, and the rest of the struct is mostly dummy.
- * (We do use canSetTag, stmt_location, stmt_len, and possibly queryId.)
- * ----------------
- */
- typedef struct PlannedStmt
- {
- NodeTag type;
-
- CmdType commandType; /* select|insert|update|delete|utility */
-
- uint64 queryId; /* query identifier (copied from Query) */
-
- bool hasReturning; /* is it insert|update|delete RETURNING? */
-
- bool hasModifyingCTE; /* has insert|update|delete in WITH? */
-
- bool canSetTag; /* do I set the command result tag? */
-
- bool transientPlan; /* redo plan when TransactionXmin changes? */
-
- bool dependsOnRole; /* is plan specific to current role? */
-
- bool parallelModeNeeded; /* parallel mode required to execute? */
-
- int jitFlags; /* which forms of JIT should be performed */
-
- struct Plan *planTree; /* tree of Plan nodes */
-
- List *rtable; /* list of RangeTblEntry nodes */
-
- /* rtable indexes of target relations for INSERT/UPDATE/DELETE */
- List *resultRelations; /* integer list of RT indexes, or NIL */
-
- /*
- * rtable indexes of partitioned table roots that are UPDATE/DELETE
- * targets; needed for trigger firing.
- */
- List *rootResultRelations;
-
- List *subplans; /* Plan trees for SubPlan expressions; note
- * that some could be NULL */
-
- Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
-
- List *rowMarks; /* a list of PlanRowMark's */
-
- List *relationOids; /* OIDs of relations the plan depends on */
-
- List *invalItems; /* other dependencies, as PlanInvalItems */
-
- List *paramExecTypes; /* type OIDs for PARAM_EXEC Params */
-
- Node *utilityStmt; /* non-null if this is utility stmt */
-
- /* statement location in source string (copied from Query) */
- int stmt_location; /* start location, or -1 if unknown */
- int stmt_len; /* length in bytes; 0 means "rest of string" */
- } PlannedStmt;
-
- /* macro for fetching the Plan associated with a SubPlan node */
- #define exec_subplan_get_plan(plannedstmt, subplan) \
- ((Plan *) list_nth((plannedstmt)->subplans, (subplan)->plan_id - 1))
-
-
- /* ----------------
- * Plan node
- *
- * All plan nodes "derive" from the Plan structure by having the
- * Plan structure as the first field. This ensures that everything works
- * when nodes are cast to Plan's. (node pointers are frequently cast to Plan*
- * when passed around generically in the executor)
- *
- * We never actually instantiate any Plan nodes; this is just the common
- * abstract superclass for all Plan-type nodes.
- * ----------------
- */
- typedef struct Plan
- {
- NodeTag type;
-
- /*
- * estimated execution costs for plan (see costsize.c for more info)
- */
- Cost startup_cost; /* cost expended before fetching any tuples */
- Cost total_cost; /* total cost (assuming all tuples fetched) */
-
- /*
- * planner's estimate of result size of this plan step
- */
- double plan_rows; /* number of rows plan is expected to emit */
- int plan_width; /* average row width in bytes */
-
- /*
- * information needed for parallel query
- */
- bool parallel_aware; /* engage parallel-aware logic? */
- bool parallel_safe; /* OK to use as part of parallel plan? */
-
- /*
- * Common structural data for all Plan types.
- */
- int plan_node_id; /* unique across entire final plan tree */
- List *targetlist; /* target list to be computed at this node */
- List *qual; /* implicitly-ANDed qual conditions */
- struct Plan *lefttree; /* input plan tree(s) */
- struct Plan *righttree;
- List *initPlan; /* Init Plan nodes (un-correlated expr
- * subselects) */
-
- /*
- * Information for management of parameter-change-driven rescanning
- *
- * extParam includes the paramIDs of all external PARAM_EXEC params
- * affecting this plan node or its children. setParam params from the
- * node's initPlans are not included, but their extParams are.
- *
- * allParam includes all the extParam paramIDs, plus the IDs of local
- * params that affect the node (i.e., the setParams of its initplans).
- * These are _all_ the PARAM_EXEC params that affect this node.
- */
- Bitmapset *extParam;
- Bitmapset *allParam;
- } Plan;
-
- /* ----------------
- * these are defined to avoid confusion problems with "left"
- * and "right" and "inner" and "outer". The convention is that
- * the "left" plan is the "outer" plan and the "right" plan is
- * the inner plan, but these make the code more readable.
- * ----------------
- */
- #define innerPlan(node) (((Plan *)(node))->righttree)
- #define outerPlan(node) (((Plan *)(node))->lefttree)
-
-
- /* ----------------
- * Result node -
- * If no outer plan, evaluate a variable-free targetlist.
- * If outer plan, return tuples from outer plan (after a level of
- * projection as shown by targetlist).
- *
- * If resconstantqual isn't NULL, it represents a one-time qualification
- * test (i.e., one that doesn't depend on any variables from the outer plan,
- * so needs to be evaluated only once).
- * ----------------
- */
- typedef struct Result
- {
- Plan plan;
- Node *resconstantqual;
- } Result;
-
- /* ----------------
- * ProjectSet node -
- * Apply a projection that includes set-returning functions to the
- * output tuples of the outer plan.
- * ----------------
- */
- typedef struct ProjectSet
- {
- Plan plan;
- } ProjectSet;
-
- /* ----------------
- * ModifyTable node -
- * Apply rows produced by subplan(s) to result table(s),
- * by inserting, updating, or deleting.
- *
- * If the originally named target table is a partitioned table, both
- * nominalRelation and rootRelation contain the RT index of the partition
- * root, which is not otherwise mentioned in the plan. Otherwise rootRelation
- * is zero. However, nominalRelation will always be set, as it's the rel that
- * EXPLAIN should claim is the INSERT/UPDATE/DELETE target.
- *
- * Note that rowMarks and epqParam are presumed to be valid for all the
- * subplan(s); they can't contain any info that varies across subplans.
- * ----------------
- */
- typedef struct ModifyTable
- {
- Plan plan;
- CmdType operation; /* INSERT, UPDATE, or DELETE */
- bool canSetTag; /* do we set the command tag/es_processed? */
- Index nominalRelation; /* Parent RT index for use of EXPLAIN */
- Index rootRelation; /* Root RT index, if target is partitioned */
- bool partColsUpdated; /* some part key in hierarchy updated */
- List *resultRelations; /* integer list of RT indexes */
- int resultRelIndex; /* index of first resultRel in plan's list */
- int rootResultRelIndex; /* index of the partitioned table root */
- List *plans; /* plan(s) producing source data */
- List *withCheckOptionLists; /* per-target-table WCO lists */
- List *returningLists; /* per-target-table RETURNING tlists */
- List *fdwPrivLists; /* per-target-table FDW private data lists */
- Bitmapset *fdwDirectModifyPlans; /* indices of FDW DM plans */
- List *rowMarks; /* PlanRowMarks (non-locking only) */
- int epqParam; /* ID of Param for EvalPlanQual re-eval */
- OnConflictAction onConflictAction; /* ON CONFLICT action */
- List *arbiterIndexes; /* List of ON CONFLICT arbiter index OIDs */
- List *onConflictSet; /* SET for INSERT ON CONFLICT DO UPDATE */
- Node *onConflictWhere; /* WHERE for ON CONFLICT UPDATE */
- Index exclRelRTI; /* RTI of the EXCLUDED pseudo relation */
- List *exclRelTlist; /* tlist of the EXCLUDED pseudo relation */
- } ModifyTable;
-
- struct PartitionPruneInfo; /* forward reference to struct below */
-
- /* ----------------
- * Append node -
- * Generate the concatenation of the results of sub-plans.
- * ----------------
- */
- typedef struct Append
- {
- Plan plan;
- List *appendplans;
-
- /*
- * All 'appendplans' preceding this index are non-partial plans. All
- * 'appendplans' from this index onwards are partial plans.
- */
- int first_partial_plan;
-
- /* Info for run-time subplan pruning; NULL if we're not doing that */
- struct PartitionPruneInfo *part_prune_info;
- } Append;
-
- /* ----------------
- * MergeAppend node -
- * Merge the results of pre-sorted sub-plans to preserve the ordering.
- * ----------------
- */
- typedef struct MergeAppend
- {
- Plan plan;
- List *mergeplans;
- /* these fields are just like the sort-key info in struct Sort: */
- int numCols; /* number of sort-key columns */
- AttrNumber *sortColIdx; /* their indexes in the target list */
- Oid *sortOperators; /* OIDs of operators to sort them by */
- Oid *collations; /* OIDs of collations */
- bool *nullsFirst; /* NULLS FIRST/LAST directions */
- /* Info for run-time subplan pruning; NULL if we're not doing that */
- struct PartitionPruneInfo *part_prune_info;
- } MergeAppend;
-
- /* ----------------
- * RecursiveUnion node -
- * Generate a recursive union of two subplans.
- *
- * The "outer" subplan is always the non-recursive term, and the "inner"
- * subplan is the recursive term.
- * ----------------
- */
- typedef struct RecursiveUnion
- {
- Plan plan;
- int wtParam; /* ID of Param representing work table */
- /* Remaining fields are zero/null in UNION ALL case */
- int numCols; /* number of columns to check for
- * duplicate-ness */
- AttrNumber *dupColIdx; /* their indexes in the target list */
- Oid *dupOperators; /* equality operators to compare with */
- Oid *dupCollations;
- long numGroups; /* estimated number of groups in input */
- } RecursiveUnion;
-
- /* ----------------
- * BitmapAnd node -
- * Generate the intersection of the results of sub-plans.
- *
- * The subplans must be of types that yield tuple bitmaps. The targetlist
- * and qual fields of the plan are unused and are always NIL.
- * ----------------
- */
- typedef struct BitmapAnd
- {
- Plan plan;
- List *bitmapplans;
- } BitmapAnd;
-
- /* ----------------
- * BitmapOr node -
- * Generate the union of the results of sub-plans.
- *
- * The subplans must be of types that yield tuple bitmaps. The targetlist
- * and qual fields of the plan are unused and are always NIL.
- * ----------------
- */
- typedef struct BitmapOr
- {
- Plan plan;
- bool isshared;
- List *bitmapplans;
- } BitmapOr;
-
- /*
- * ==========
- * Scan nodes
- * ==========
- */
- typedef struct Scan
- {
- Plan plan;
- Index scanrelid; /* relid is index into the range table */
- } Scan;
-
- /* ----------------
- * sequential scan node
- * ----------------
- */
- typedef Scan SeqScan;
-
- /* ----------------
- * table sample scan node
- * ----------------
- */
- typedef struct SampleScan
- {
- Scan scan;
- /* use struct pointer to avoid including parsenodes.h here */
- struct TableSampleClause *tablesample;
- } SampleScan;
-
- /* ----------------
- * index scan node
- *
- * indexqualorig is an implicitly-ANDed list of index qual expressions, each
- * in the same form it appeared in the query WHERE condition. Each should
- * be of the form (indexkey OP comparisonval) or (comparisonval OP indexkey).
- * The indexkey is a Var or expression referencing column(s) of the index's
- * base table. The comparisonval might be any expression, but it won't use
- * any columns of the base table. The expressions are ordered by index
- * column position (but items referencing the same index column can appear
- * in any order). indexqualorig is used at runtime only if we have to recheck
- * a lossy indexqual.
- *
- * indexqual has the same form, but the expressions have been commuted if
- * necessary to put the indexkeys on the left, and the indexkeys are replaced
- * by Var nodes identifying the index columns (their varno is INDEX_VAR and
- * their varattno is the index column number).
- *
- * indexorderbyorig is similarly the original form of any ORDER BY expressions
- * that are being implemented by the index, while indexorderby is modified to
- * have index column Vars on the left-hand side. Here, multiple expressions
- * must appear in exactly the ORDER BY order, and this is not necessarily the
- * index column order. Only the expressions are provided, not the auxiliary
- * sort-order information from the ORDER BY SortGroupClauses; it's assumed
- * that the sort ordering is fully determinable from the top-level operators.
- * indexorderbyorig is used at runtime to recheck the ordering, if the index
- * cannot calculate an accurate ordering. It is also needed for EXPLAIN.
- *
- * indexorderbyops is a list of the OIDs of the operators used to sort the
- * ORDER BY expressions. This is used together with indexorderbyorig to
- * recheck ordering at run time. (Note that indexorderby, indexorderbyorig,
- * and indexorderbyops are used for amcanorderbyop cases, not amcanorder.)
- *
- * indexorderdir specifies the scan ordering, for indexscans on amcanorder
- * indexes (for other indexes it should be "don't care").
- * ----------------
- */
- typedef struct IndexScan
- {
- Scan scan;
- Oid indexid; /* OID of index to scan */
- List *indexqual; /* list of index quals (usually OpExprs) */
- List *indexqualorig; /* the same in original form */
- List *indexorderby; /* list of index ORDER BY exprs */
- List *indexorderbyorig; /* the same in original form */
- List *indexorderbyops; /* OIDs of sort ops for ORDER BY exprs */
- ScanDirection indexorderdir; /* forward or backward or don't care */
- } IndexScan;
-
- /* ----------------
- * index-only scan node
- *
- * IndexOnlyScan is very similar to IndexScan, but it specifies an
- * index-only scan, in which the data comes from the index not the heap.
- * Because of this, *all* Vars in the plan node's targetlist, qual, and
- * index expressions reference index columns and have varno = INDEX_VAR.
- * Hence we do not need separate indexqualorig and indexorderbyorig lists,
- * since their contents would be equivalent to indexqual and indexorderby.
- *
- * To help EXPLAIN interpret the index Vars for display, we provide
- * indextlist, which represents the contents of the index as a targetlist
- * with one TLE per index column. Vars appearing in this list reference
- * the base table, and this is the only field in the plan node that may
- * contain such Vars.
- * ----------------
- */
- typedef struct IndexOnlyScan
- {
- Scan scan;
- Oid indexid; /* OID of index to scan */
- List *indexqual; /* list of index quals (usually OpExprs) */
- List *indexorderby; /* list of index ORDER BY exprs */
- List *indextlist; /* TargetEntry list describing index's cols */
- ScanDirection indexorderdir; /* forward or backward or don't care */
- } IndexOnlyScan;
-
- /* ----------------
- * bitmap index scan node
- *
- * BitmapIndexScan delivers a bitmap of potential tuple locations;
- * it does not access the heap itself. The bitmap is used by an
- * ancestor BitmapHeapScan node, possibly after passing through
- * intermediate BitmapAnd and/or BitmapOr nodes to combine it with
- * the results of other BitmapIndexScans.
- *
- * The fields have the same meanings as for IndexScan, except we don't
- * store a direction flag because direction is uninteresting.
- *
- * In a BitmapIndexScan plan node, the targetlist and qual fields are
- * not used and are always NIL. The indexqualorig field is unused at
- * run time too, but is saved for the benefit of EXPLAIN.
- * ----------------
- */
- typedef struct BitmapIndexScan
- {
- Scan scan;
- Oid indexid; /* OID of index to scan */
- bool isshared; /* Create shared bitmap if set */
- List *indexqual; /* list of index quals (OpExprs) */
- List *indexqualorig; /* the same in original form */
- } BitmapIndexScan;
-
- /* ----------------
- * bitmap sequential scan node
- *
- * This needs a copy of the qual conditions being used by the input index
- * scans because there are various cases where we need to recheck the quals;
- * for example, when the bitmap is lossy about the specific rows on a page
- * that meet the index condition.
- * ----------------
- */
- typedef struct BitmapHeapScan
- {
- Scan scan;
- List *bitmapqualorig; /* index quals, in standard expr form */
- } BitmapHeapScan;
-
- /* ----------------
- * tid scan node
- *
- * tidquals is an implicitly OR'ed list of qual expressions of the form
- * "CTID = pseudoconstant", or "CTID = ANY(pseudoconstant_array)",
- * or a CurrentOfExpr for the relation.
- * ----------------
- */
- typedef struct TidScan
- {
- Scan scan;
- List *tidquals; /* qual(s) involving CTID = something */
- } TidScan;
-
- /* ----------------
- * subquery scan node
- *
- * SubqueryScan is for scanning the output of a sub-query in the range table.
- * We often need an extra plan node above the sub-query's plan to perform
- * expression evaluations (which we can't push into the sub-query without
- * risking changing its semantics). Although we are not scanning a physical
- * relation, we make this a descendant of Scan anyway for code-sharing
- * purposes.
- *
- * Note: we store the sub-plan in the type-specific subplan field, not in
- * the generic lefttree field as you might expect. This is because we do
- * not want plan-tree-traversal routines to recurse into the subplan without
- * knowing that they are changing Query contexts.
- * ----------------
- */
- typedef struct SubqueryScan
- {
- Scan scan;
- Plan *subplan;
- } SubqueryScan;
-
- /* ----------------
- * FunctionScan node
- * ----------------
- */
- typedef struct FunctionScan
- {
- Scan scan;
- List *functions; /* list of RangeTblFunction nodes */
- bool funcordinality; /* WITH ORDINALITY */
- } FunctionScan;
-
- /* ----------------
- * ValuesScan node
- * ----------------
- */
- typedef struct ValuesScan
- {
- Scan scan;
- List *values_lists; /* list of expression lists */
- } ValuesScan;
-
- /* ----------------
- * TableFunc scan node
- * ----------------
- */
- typedef struct TableFuncScan
- {
- Scan scan;
- TableFunc *tablefunc; /* table function node */
- } TableFuncScan;
-
- /* ----------------
- * CteScan node
- * ----------------
- */
- typedef struct CteScan
- {
- Scan scan;
- int ctePlanId; /* ID of init SubPlan for CTE */
- int cteParam; /* ID of Param representing CTE output */
- } CteScan;
-
- /* ----------------
- * NamedTuplestoreScan node
- * ----------------
- */
- typedef struct NamedTuplestoreScan
- {
- Scan scan;
- char *enrname; /* Name given to Ephemeral Named Relation */
- } NamedTuplestoreScan;
-
- /* ----------------
- * WorkTableScan node
- * ----------------
- */
- typedef struct WorkTableScan
- {
- Scan scan;
- int wtParam; /* ID of Param representing work table */
- } WorkTableScan;
-
- /* ----------------
- * ForeignScan node
- *
- * fdw_exprs and fdw_private are both under the control of the foreign-data
- * wrapper, but fdw_exprs is presumed to contain expression trees and will
- * be post-processed accordingly by the planner; fdw_private won't be.
- * Note that everything in both lists must be copiable by copyObject().
- * One way to store an arbitrary blob of bytes is to represent it as a bytea
- * Const. Usually, though, you'll be better off choosing a representation
- * that can be dumped usefully by nodeToString().
- *
- * fdw_scan_tlist is a targetlist describing the contents of the scan tuple
- * returned by the FDW; it can be NIL if the scan tuple matches the declared
- * rowtype of the foreign table, which is the normal case for a simple foreign
- * table scan. (If the plan node represents a foreign join, fdw_scan_tlist
- * is required since there is no rowtype available from the system catalogs.)
- * When fdw_scan_tlist is provided, Vars in the node's tlist and quals must
- * have varno INDEX_VAR, and their varattnos correspond to resnos in the
- * fdw_scan_tlist (which are also column numbers in the actual scan tuple).
- * fdw_scan_tlist is never actually executed; it just holds expression trees
- * describing what is in the scan tuple's columns.
- *
- * fdw_recheck_quals should contain any quals which the core system passed to
- * the FDW but which were not added to scan.plan.qual; that is, it should
- * contain the quals being checked remotely. This is needed for correct
- * behavior during EvalPlanQual rechecks.
- *
- * When the plan node represents a foreign join, scan.scanrelid is zero and
- * fs_relids must be consulted to identify the join relation. (fs_relids
- * is valid for simple scans as well, but will always match scan.scanrelid.)
- * ----------------
- */
- typedef struct ForeignScan
- {
- Scan scan;
- CmdType operation; /* SELECT/INSERT/UPDATE/DELETE */
- Oid fs_server; /* OID of foreign server */
- List *fdw_exprs; /* expressions that FDW may evaluate */
- List *fdw_private; /* private data for FDW */
- List *fdw_scan_tlist; /* optional tlist describing scan tuple */
- List *fdw_recheck_quals; /* original quals not in scan.plan.qual */
- Bitmapset *fs_relids; /* RTIs generated by this scan */
- bool fsSystemCol; /* true if any "system column" is needed */
- } ForeignScan;
-
- /* ----------------
- * CustomScan node
- *
- * The comments for ForeignScan's fdw_exprs, fdw_private, fdw_scan_tlist,
- * and fs_relids fields apply equally to CustomScan's custom_exprs,
- * custom_private, custom_scan_tlist, and custom_relids fields. The
- * convention of setting scan.scanrelid to zero for joins applies as well.
- *
- * Note that since Plan trees can be copied, custom scan providers *must*
- * fit all plan data they need into those fields; embedding CustomScan in
- * a larger struct will not work.
- * ----------------
- */
- struct CustomScanMethods;
-
- typedef struct CustomScan
- {
- Scan scan;
- uint32 flags; /* mask of CUSTOMPATH_* flags, see
- * nodes/extensible.h */
- List *custom_plans; /* list of Plan nodes, if any */
- List *custom_exprs; /* expressions that custom code may evaluate */
- List *custom_private; /* private data for custom code */
- List *custom_scan_tlist; /* optional tlist describing scan tuple */
- Bitmapset *custom_relids; /* RTIs generated by this scan */
- const struct CustomScanMethods *methods;
- } CustomScan;
-
- /*
- * ==========
- * Join nodes
- * ==========
- */
-
- /* ----------------
- * Join node
- *
- * jointype: rule for joining tuples from left and right subtrees
- * inner_unique each outer tuple can match to no more than one inner tuple
- * joinqual: qual conditions that came from JOIN/ON or JOIN/USING
- * (plan.qual contains conditions that came from WHERE)
- *
- * When jointype is INNER, joinqual and plan.qual are semantically
- * interchangeable. For OUTER jointypes, the two are *not* interchangeable;
- * only joinqual is used to determine whether a match has been found for
- * the purpose of deciding whether to generate null-extended tuples.
- * (But plan.qual is still applied before actually returning a tuple.)
- * For an outer join, only joinquals are allowed to be used as the merge
- * or hash condition of a merge or hash join.
- *
- * inner_unique is set if the joinquals are such that no more than one inner
- * tuple could match any given outer tuple. This allows the executor to
- * skip searching for additional matches. (This must be provable from just
- * the joinquals, ignoring plan.qual, due to where the executor tests it.)
- * ----------------
- */
- typedef struct Join
- {
- Plan plan;
- JoinType jointype;
- bool inner_unique;
- List *joinqual; /* JOIN quals (in addition to plan.qual) */
- } Join;
-
- /* ----------------
- * nest loop join node
- *
- * The nestParams list identifies any executor Params that must be passed
- * into execution of the inner subplan carrying values from the current row
- * of the outer subplan. Currently we restrict these values to be simple
- * Vars, but perhaps someday that'd be worth relaxing. (Note: during plan
- * creation, the paramval can actually be a PlaceHolderVar expression; but it
- * must be a Var with varno OUTER_VAR by the time it gets to the executor.)
- * ----------------
- */
- typedef struct NestLoop
- {
- Join join;
- List *nestParams; /* list of NestLoopParam nodes */
- } NestLoop;
-
- typedef struct NestLoopParam
- {
- NodeTag type;
- int paramno; /* number of the PARAM_EXEC Param to set */
- Var *paramval; /* outer-relation Var to assign to Param */
- } NestLoopParam;
-
- /* ----------------
- * merge join node
- *
- * The expected ordering of each mergeable column is described by a btree
- * opfamily OID, a collation OID, a direction (BTLessStrategyNumber or
- * BTGreaterStrategyNumber) and a nulls-first flag. Note that the two sides
- * of each mergeclause may be of different datatypes, but they are ordered the
- * same way according to the common opfamily and collation. The operator in
- * each mergeclause must be an equality operator of the indicated opfamily.
- * ----------------
- */
- typedef struct MergeJoin
- {
- Join join;
- bool skip_mark_restore; /* Can we skip mark/restore calls? */
- List *mergeclauses; /* mergeclauses as expression trees */
- /* these are arrays, but have the same length as the mergeclauses list: */
- Oid *mergeFamilies; /* per-clause OIDs of btree opfamilies */
- Oid *mergeCollations; /* per-clause OIDs of collations */
- int *mergeStrategies; /* per-clause ordering (ASC or DESC) */
- bool *mergeNullsFirst; /* per-clause nulls ordering */
- } MergeJoin;
-
- /* ----------------
- * hash join node
- * ----------------
- */
- typedef struct HashJoin
- {
- Join join;
- List *hashclauses;
- List *hashoperators;
- List *hashcollations;
-
- /*
- * List of expressions to be hashed for tuples from the outer plan, to
- * perform lookups in the hashtable over the inner plan.
- */
- List *hashkeys;
- } HashJoin;
-
- /* ----------------
- * materialization node
- * ----------------
- */
- typedef struct Material
- {
- Plan plan;
- } Material;
-
- /* ----------------
- * sort node
- * ----------------
- */
- typedef struct Sort
- {
- Plan plan;
- int numCols; /* number of sort-key columns */
- AttrNumber *sortColIdx; /* their indexes in the target list */
- Oid *sortOperators; /* OIDs of operators to sort them by */
- Oid *collations; /* OIDs of collations */
- bool *nullsFirst; /* NULLS FIRST/LAST directions */
- } Sort;
-
- /* ---------------
- * group node -
- * Used for queries with GROUP BY (but no aggregates) specified.
- * The input must be presorted according to the grouping columns.
- * ---------------
- */
- typedef struct Group
- {
- Plan plan;
- int numCols; /* number of grouping columns */
- AttrNumber *grpColIdx; /* their indexes in the target list */
- Oid *grpOperators; /* equality operators to compare with */
- Oid *grpCollations;
- } Group;
-
- /* ---------------
- * aggregate node
- *
- * An Agg node implements plain or grouped aggregation. For grouped
- * aggregation, we can work with presorted input or unsorted input;
- * the latter strategy uses an internal hashtable.
- *
- * Notice the lack of any direct info about the aggregate functions to be
- * computed. They are found by scanning the node's tlist and quals during
- * executor startup. (It is possible that there are no aggregate functions;
- * this could happen if they get optimized away by constant-folding, or if
- * we are using the Agg node to implement hash-based grouping.)
- * ---------------
- */
- typedef struct Agg
- {
- Plan plan;
- AggStrategy aggstrategy; /* basic strategy, see nodes.h */
- AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
- int numCols; /* number of grouping columns */
- AttrNumber *grpColIdx; /* their indexes in the target list */
- Oid *grpOperators; /* equality operators to compare with */
- Oid *grpCollations;
- long numGroups; /* estimated number of groups in input */
- Bitmapset *aggParams; /* IDs of Params used in Aggref inputs */
- /* Note: planner provides numGroups & aggParams only in HASHED/MIXED case */
- List *groupingSets; /* grouping sets to use */
- List *chain; /* chained Agg/Sort nodes */
- } Agg;
-
- /* ----------------
- * window aggregate node
- * ----------------
- */
- typedef struct WindowAgg
- {
- Plan plan;
- Index winref; /* ID referenced by window functions */
- int partNumCols; /* number of columns in partition clause */
- AttrNumber *partColIdx; /* their indexes in the target list */
- Oid *partOperators; /* equality operators for partition columns */
- Oid *partCollations; /* collations for partition columns */
- int ordNumCols; /* number of columns in ordering clause */
- AttrNumber *ordColIdx; /* their indexes in the target list */
- Oid *ordOperators; /* equality operators for ordering columns */
- Oid *ordCollations; /* collations for ordering columns */
- int frameOptions; /* frame_clause options, see WindowDef */
- Node *startOffset; /* expression for starting bound, if any */
- Node *endOffset; /* expression for ending bound, if any */
- /* these fields are used with RANGE offset PRECEDING/FOLLOWING: */
- Oid startInRangeFunc; /* in_range function for startOffset */
- Oid endInRangeFunc; /* in_range function for endOffset */
- Oid inRangeColl; /* collation for in_range tests */
- bool inRangeAsc; /* use ASC sort order for in_range tests? */
- bool inRangeNullsFirst; /* nulls sort first for in_range tests? */
- } WindowAgg;
-
- /* ----------------
- * unique node
- * ----------------
- */
- typedef struct Unique
- {
- Plan plan;
- int numCols; /* number of columns to check for uniqueness */
- AttrNumber *uniqColIdx; /* their indexes in the target list */
- Oid *uniqOperators; /* equality operators to compare with */
- Oid *uniqCollations; /* collations for equality comparisons */
- } Unique;
-
- /* ------------
- * gather node
- *
- * Note: rescan_param is the ID of a PARAM_EXEC parameter slot. That slot
- * will never actually contain a value, but the Gather node must flag it as
- * having changed whenever it is rescanned. The child parallel-aware scan
- * nodes are marked as depending on that parameter, so that the rescan
- * machinery is aware that their output is likely to change across rescans.
- * In some cases we don't need a rescan Param, so rescan_param is set to -1.
- * ------------
- */
- typedef struct Gather
- {
- Plan plan;
- int num_workers; /* planned number of worker processes */
- int rescan_param; /* ID of Param that signals a rescan, or -1 */
- bool single_copy; /* don't execute plan more than once */
- bool invisible; /* suppress EXPLAIN display (for testing)? */
- Bitmapset *initParam; /* param id's of initplans which are referred
- * at gather or one of it's child node */
- } Gather;
-
- /* ------------
- * gather merge node
- * ------------
- */
- typedef struct GatherMerge
- {
- Plan plan;
- int num_workers; /* planned number of worker processes */
- int rescan_param; /* ID of Param that signals a rescan, or -1 */
- /* remaining fields are just like the sort-key info in struct Sort */
- int numCols; /* number of sort-key columns */
- AttrNumber *sortColIdx; /* their indexes in the target list */
- Oid *sortOperators; /* OIDs of operators to sort them by */
- Oid *collations; /* OIDs of collations */
- bool *nullsFirst; /* NULLS FIRST/LAST directions */
- Bitmapset *initParam; /* param id's of initplans which are referred
- * at gather merge or one of it's child node */
- } GatherMerge;
-
- /* ----------------
- * hash build node
- *
- * If the executor is supposed to try to apply skew join optimization, then
- * skewTable/skewColumn/skewInherit identify the outer relation's join key
- * column, from which the relevant MCV statistics can be fetched.
- * ----------------
- */
- typedef struct Hash
- {
- Plan plan;
-
- /*
- * List of expressions to be hashed for tuples from Hash's outer plan,
- * needed to put them into the hashtable.
- */
- List *hashkeys; /* hash keys for the hashjoin condition */
- Oid skewTable; /* outer join key's table OID, or InvalidOid */
- AttrNumber skewColumn; /* outer join key's column #, or zero */
- bool skewInherit; /* is outer join rel an inheritance tree? */
- /* all other info is in the parent HashJoin node */
- double rows_total; /* estimate total rows if parallel_aware */
- } Hash;
-
- /* ----------------
- * setop node
- * ----------------
- */
- typedef struct SetOp
- {
- Plan plan;
- SetOpCmd cmd; /* what to do, see nodes.h */
- SetOpStrategy strategy; /* how to do it, see nodes.h */
- int numCols; /* number of columns to check for
- * duplicate-ness */
- AttrNumber *dupColIdx; /* their indexes in the target list */
- Oid *dupOperators; /* equality operators to compare with */
- Oid *dupCollations;
- AttrNumber flagColIdx; /* where is the flag column, if any */
- int firstFlag; /* flag value for first input relation */
- long numGroups; /* estimated number of groups in input */
- } SetOp;
-
- /* ----------------
- * lock-rows node
- *
- * rowMarks identifies the rels to be locked by this node; it should be
- * a subset of the rowMarks listed in the top-level PlannedStmt.
- * epqParam is a Param that all scan nodes below this one must depend on.
- * It is used to force re-evaluation of the plan during EvalPlanQual.
- * ----------------
- */
- typedef struct LockRows
- {
- Plan plan;
- List *rowMarks; /* a list of PlanRowMark's */
- int epqParam; /* ID of Param for EvalPlanQual re-eval */
- } LockRows;
-
- /* ----------------
- * limit node
- *
- * Note: as of Postgres 8.2, the offset and count expressions are expected
- * to yield int8, rather than int4 as before.
- * ----------------
- */
- typedef struct Limit
- {
- Plan plan;
- Node *limitOffset; /* OFFSET parameter, or NULL if none */
- Node *limitCount; /* COUNT parameter, or NULL if none */
- } Limit;
-
-
- /*
- * RowMarkType -
- * enums for types of row-marking operations
- *
- * The first four of these values represent different lock strengths that
- * we can take on tuples according to SELECT FOR [KEY] UPDATE/SHARE requests.
- * We support these on regular tables, as well as on foreign tables whose FDWs
- * report support for late locking. For other foreign tables, any locking
- * that might be done for such requests must happen during the initial row
- * fetch; their FDWs provide no mechanism for going back to lock a row later.
- * This means that the semantics will be a bit different than for a local
- * table; in particular we are likely to lock more rows than would be locked
- * locally, since remote rows will be locked even if they then fail
- * locally-checked restriction or join quals. However, the prospect of
- * doing a separate remote query to lock each selected row is usually pretty
- * unappealing, so early locking remains a credible design choice for FDWs.
- *
- * When doing UPDATE, DELETE, or SELECT FOR UPDATE/SHARE, we have to uniquely
- * identify all the source rows, not only those from the target relations, so
- * that we can perform EvalPlanQual rechecking at need. For plain tables we
- * can just fetch the TID, much as for a target relation; this case is
- * represented by ROW_MARK_REFERENCE. Otherwise (for example for VALUES or
- * FUNCTION scans) we have to copy the whole row value. ROW_MARK_COPY is
- * pretty inefficient, since most of the time we'll never need the data; but
- * fortunately the overhead is usually not performance-critical in practice.
- * By default we use ROW_MARK_COPY for foreign tables, but if the FDW has
- * a concept of rowid it can request to use ROW_MARK_REFERENCE instead.
- * (Again, this probably doesn't make sense if a physical remote fetch is
- * needed, but for FDWs that map to local storage it might be credible.)
- */
- typedef enum RowMarkType
- {
- ROW_MARK_EXCLUSIVE, /* obtain exclusive tuple lock */
- ROW_MARK_NOKEYEXCLUSIVE, /* obtain no-key exclusive tuple lock */
- ROW_MARK_SHARE, /* obtain shared tuple lock */
- ROW_MARK_KEYSHARE, /* obtain keyshare tuple lock */
- ROW_MARK_REFERENCE, /* just fetch the TID, don't lock it */
- ROW_MARK_COPY /* physically copy the row value */
- } RowMarkType;
-
- #define RowMarkRequiresRowShareLock(marktype) ((marktype) <= ROW_MARK_KEYSHARE)
-
- /*
- * PlanRowMark -
- * plan-time representation of FOR [KEY] UPDATE/SHARE clauses
- *
- * When doing UPDATE, DELETE, or SELECT FOR UPDATE/SHARE, we create a separate
- * PlanRowMark node for each non-target relation in the query. Relations that
- * are not specified as FOR UPDATE/SHARE are marked ROW_MARK_REFERENCE (if
- * regular tables or supported foreign tables) or ROW_MARK_COPY (if not).
- *
- * Initially all PlanRowMarks have rti == prti and isParent == false.
- * When the planner discovers that a relation is the root of an inheritance
- * tree, it sets isParent true, and adds an additional PlanRowMark to the
- * list for each child relation (including the target rel itself in its role
- * as a child). isParent is also set to true for the partitioned child
- * relations, which are not scanned just like the root parent. The child
- * entries have rti == child rel's RT index and prti == parent's RT index,
- * and can therefore be recognized as children by the fact that prti != rti.
- * The parent's allMarkTypes field gets the OR of (1<<markType) across all
- * its children (this definition allows children to use different markTypes).
- *
- * The planner also adds resjunk output columns to the plan that carry
- * information sufficient to identify the locked or fetched rows. When
- * markType != ROW_MARK_COPY, these columns are named
- * tableoid%u OID of table
- * ctid%u TID of row
- * The tableoid column is only present for an inheritance hierarchy.
- * When markType == ROW_MARK_COPY, there is instead a single column named
- * wholerow%u whole-row value of relation
- * (An inheritance hierarchy could have all three resjunk output columns,
- * if some children use a different markType than others.)
- * In all three cases, %u represents the rowmark ID number (rowmarkId).
- * This number is unique within a plan tree, except that child relation
- * entries copy their parent's rowmarkId. (Assigning unique numbers
- * means we needn't renumber rowmarkIds when flattening subqueries, which
- * would require finding and renaming the resjunk columns as well.)
- * Note this means that all tables in an inheritance hierarchy share the
- * same resjunk column names. However, in an inherited UPDATE/DELETE the
- * columns could have different physical column numbers in each subplan.
- */
- typedef struct PlanRowMark
- {
- NodeTag type;
- Index rti; /* range table index of markable relation */
- Index prti; /* range table index of parent relation */
- Index rowmarkId; /* unique identifier for resjunk columns */
- RowMarkType markType; /* see enum above */
- int allMarkTypes; /* OR of (1<<markType) for all children */
- LockClauseStrength strength; /* LockingClause's strength, or LCS_NONE */
- LockWaitPolicy waitPolicy; /* NOWAIT and SKIP LOCKED options */
- bool isParent; /* true if this is a "dummy" parent entry */
- } PlanRowMark;
-
-
- /*
- * Node types to represent partition pruning information.
- */
-
- /*
- * PartitionPruneInfo - Details required to allow the executor to prune
- * partitions.
- *
- * Here we store mapping details to allow translation of a partitioned table's
- * index as returned by the partition pruning code into subplan indexes for
- * plan types which support arbitrary numbers of subplans, such as Append.
- * We also store various details to tell the executor when it should be
- * performing partition pruning.
- *
- * Each PartitionedRelPruneInfo describes the partitioning rules for a single
- * partitioned table (a/k/a level of partitioning). Since a partitioning
- * hierarchy could contain multiple levels, we represent it by a List of
- * PartitionedRelPruneInfos, where the first entry represents the topmost
- * partitioned table and additional entries represent non-leaf child
- * partitions, ordered such that parents appear before their children.
- * Then, since an Append-type node could have multiple partitioning
- * hierarchies among its children, we have an unordered List of those Lists.
- *
- * prune_infos List of Lists containing PartitionedRelPruneInfo nodes,
- * one sublist per run-time-prunable partition hierarchy
- * appearing in the parent plan node's subplans.
- * other_subplans Indexes of any subplans that are not accounted for
- * by any of the PartitionedRelPruneInfo nodes in
- * "prune_infos". These subplans must not be pruned.
- */
- typedef struct PartitionPruneInfo
- {
- NodeTag type;
- List *prune_infos;
- Bitmapset *other_subplans;
- } PartitionPruneInfo;
-
- /*
- * PartitionedRelPruneInfo - Details required to allow the executor to prune
- * partitions for a single partitioned table.
- *
- * subplan_map[] and subpart_map[] are indexed by partition index of the
- * partitioned table referenced by 'rtindex', the partition index being the
- * order that the partitions are defined in the table's PartitionDesc. For a
- * leaf partition p, subplan_map[p] contains the zero-based index of the
- * partition's subplan in the parent plan's subplan list; it is -1 if the
- * partition is non-leaf or has been pruned. For a non-leaf partition p,
- * subpart_map[p] contains the zero-based index of that sub-partition's
- * PartitionedRelPruneInfo in the hierarchy's PartitionedRelPruneInfo list;
- * it is -1 if the partition is a leaf or has been pruned. Note that subplan
- * indexes, as stored in 'subplan_map', are global across the parent plan
- * node, but partition indexes are valid only within a particular hierarchy.
- * relid_map[p] contains the partition's OID, or 0 if the partition was pruned.
- */
- typedef struct PartitionedRelPruneInfo
- {
- NodeTag type;
- Index rtindex; /* RT index of partition rel for this level */
- Bitmapset *present_parts; /* Indexes of all partitions which subplans or
- * subparts are present for */
- int nparts; /* Length of the following arrays: */
- int *subplan_map; /* subplan index by partition index, or -1 */
- int *subpart_map; /* subpart index by partition index, or -1 */
- Oid *relid_map; /* relation OID by partition index, or 0 */
-
- /*
- * initial_pruning_steps shows how to prune during executor startup (i.e.,
- * without use of any PARAM_EXEC Params); it is NIL if no startup pruning
- * is required. exec_pruning_steps shows how to prune with PARAM_EXEC
- * Params; it is NIL if no per-scan pruning is required.
- */
- List *initial_pruning_steps; /* List of PartitionPruneStep */
- List *exec_pruning_steps; /* List of PartitionPruneStep */
- Bitmapset *execparamids; /* All PARAM_EXEC Param IDs in
- * exec_pruning_steps */
- } PartitionedRelPruneInfo;
-
- /*
- * Abstract Node type for partition pruning steps (there are no concrete
- * Nodes of this type).
- *
- * step_id is the global identifier of the step within its pruning context.
- */
- typedef struct PartitionPruneStep
- {
- NodeTag type;
- int step_id;
- } PartitionPruneStep;
-
- /*
- * PartitionPruneStepOp - Information to prune using a set of mutually AND'd
- * OpExpr clauses
- *
- * This contains information extracted from up to partnatts OpExpr clauses,
- * where partnatts is the number of partition key columns. 'opstrategy' is the
- * strategy of the operator in the clause matched to the last partition key.
- * 'exprs' contains expressions which comprise the lookup key to be passed to
- * the partition bound search function. 'cmpfns' contains the OIDs of
- * comparison functions used to compare aforementioned expressions with
- * partition bounds. Both 'exprs' and 'cmpfns' contain the same number of
- * items, up to partnatts items.
- *
- * Once we find the offset of a partition bound using the lookup key, we
- * determine which partitions to include in the result based on the value of
- * 'opstrategy'. For example, if it were equality, we'd return just the
- * partition that would contain that key or a set of partitions if the key
- * didn't consist of all partitioning columns. For non-equality strategies,
- * we'd need to include other partitions as appropriate.
- *
- * 'nullkeys' is the set containing the offset of the partition keys (0 to
- * partnatts - 1) that were matched to an IS NULL clause. This is only
- * considered for hash partitioning as we need to pass which keys are null
- * to the hash partition bound search function. It is never possible to
- * have an expression be present in 'exprs' for a given partition key and
- * the corresponding bit set in 'nullkeys'.
- */
- typedef struct PartitionPruneStepOp
- {
- PartitionPruneStep step;
-
- StrategyNumber opstrategy;
- List *exprs;
- List *cmpfns;
- Bitmapset *nullkeys;
- } PartitionPruneStepOp;
-
- /*
- * PartitionPruneStepCombine - Information to prune using a BoolExpr clause
- *
- * For BoolExpr clauses, we combine the set of partitions determined for each
- * of the argument clauses.
- */
- typedef enum PartitionPruneCombineOp
- {
- PARTPRUNE_COMBINE_UNION,
- PARTPRUNE_COMBINE_INTERSECT
- } PartitionPruneCombineOp;
-
- typedef struct PartitionPruneStepCombine
- {
- PartitionPruneStep step;
-
- PartitionPruneCombineOp combineOp;
- List *source_stepids;
- } PartitionPruneStepCombine;
-
-
- /*
- * Plan invalidation info
- *
- * We track the objects on which a PlannedStmt depends in two ways:
- * relations are recorded as a simple list of OIDs, and everything else
- * is represented as a list of PlanInvalItems. A PlanInvalItem is designed
- * to be used with the syscache invalidation mechanism, so it identifies a
- * system catalog entry by cache ID and hash value.
- */
- typedef struct PlanInvalItem
- {
- NodeTag type;
- int cacheId; /* a syscache ID, see utils/syscache.h */
- uint32 hashValue; /* hash value of object's cache lookup key */
- } PlanInvalItem;
-
- #endif /* PLANNODES_H */
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