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5a7471c307
columns procost and prorows, to allow simple user adjustment of the estimated cost of a function call, as well as control of the estimated number of rows returned by a set-returning function. We might eventually wish to extend this to allow function-specific estimation routines, but there seems to be consensus that we should try a simple constant estimate first. In particular this provides a relatively simple way to control the order in which different WHERE clauses are applied in a plan node, which is a Good Thing in view of the fact that the recent EquivalenceClass planner rewrite made that much less predictable than before.
1441 lines
44 KiB
C
1441 lines
44 KiB
C
/*-------------------------------------------------------------------------
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*
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* setrefs.c
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* Post-processing of a completed plan tree: fix references to subplan
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* vars, and compute regproc values for operators
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*
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* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.128 2007/01/22 01:35:20 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "nodes/makefuncs.h"
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#include "optimizer/clauses.h"
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#include "optimizer/planmain.h"
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#include "optimizer/tlist.h"
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#include "parser/parse_expr.h"
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#include "parser/parsetree.h"
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#include "utils/lsyscache.h"
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typedef struct
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{
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Index varno; /* RT index of Var */
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AttrNumber varattno; /* attr number of Var */
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AttrNumber resno; /* TLE position of Var */
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} tlist_vinfo;
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typedef struct
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{
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List *tlist; /* underlying target list */
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int num_vars; /* number of plain Var tlist entries */
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bool has_non_vars; /* are there non-plain-Var entries? */
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/* array of num_vars entries: */
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tlist_vinfo vars[1]; /* VARIABLE LENGTH ARRAY */
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} indexed_tlist; /* VARIABLE LENGTH STRUCT */
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typedef struct
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{
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indexed_tlist *outer_itlist;
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indexed_tlist *inner_itlist;
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Index acceptable_rel;
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} join_references_context;
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typedef struct
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{
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indexed_tlist *subplan_itlist;
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Index subvarno;
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} replace_vars_with_subplan_refs_context;
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static Plan *set_subqueryscan_references(SubqueryScan *plan, List *rtable);
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static bool trivial_subqueryscan(SubqueryScan *plan);
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static void adjust_plan_varnos(Plan *plan, int rtoffset);
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static void adjust_expr_varnos(Node *node, int rtoffset);
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static bool adjust_expr_varnos_walker(Node *node, int *context);
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static void fix_expr_references(Plan *plan, Node *node);
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static bool fix_expr_references_walker(Node *node, void *context);
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static void set_join_references(Join *join);
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static void set_inner_join_references(Plan *inner_plan,
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indexed_tlist *outer_itlist);
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static void set_uppernode_references(Plan *plan, Index subvarno);
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static indexed_tlist *build_tlist_index(List *tlist);
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static Var *search_indexed_tlist_for_var(Var *var,
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indexed_tlist *itlist,
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Index newvarno);
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static Var *search_indexed_tlist_for_non_var(Node *node,
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indexed_tlist *itlist,
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Index newvarno);
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static List *join_references(List *clauses,
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indexed_tlist *outer_itlist,
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indexed_tlist *inner_itlist,
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Index acceptable_rel);
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static Node *join_references_mutator(Node *node,
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join_references_context *context);
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static Node *replace_vars_with_subplan_refs(Node *node,
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indexed_tlist *subplan_itlist,
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Index subvarno);
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static Node *replace_vars_with_subplan_refs_mutator(Node *node,
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replace_vars_with_subplan_refs_context *context);
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static bool fix_opfuncids_walker(Node *node, void *context);
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/*****************************************************************************
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*
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* SUBPLAN REFERENCES
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*
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*****************************************************************************/
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/*
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* set_plan_references
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*
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* This is the final processing pass of the planner/optimizer. The plan
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* tree is complete; we just have to adjust some representational details
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* for the convenience of the executor. We update Vars in upper plan nodes
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* to refer to the outputs of their subplans, and we compute regproc OIDs
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* for operators (ie, we look up the function that implements each op).
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*
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* We also perform one final optimization step, which is to delete
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* SubqueryScan plan nodes that aren't doing anything useful (ie, have
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* no qual and a no-op targetlist). The reason for doing this last is that
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* it can't readily be done before set_plan_references, because it would
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* break set_uppernode_references: the Vars in the subquery's top tlist
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* won't match up with the Vars in the outer plan tree. The SubqueryScan
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* serves a necessary function as a buffer between outer query and subquery
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* variable numbering ... but the executor doesn't care about that, only the
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* planner.
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*
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* set_plan_references recursively traverses the whole plan tree.
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*
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* The return value is normally the same Plan node passed in, but can be
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* different when the passed-in Plan is a SubqueryScan we decide isn't needed.
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*
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* Note: to delete a SubqueryScan, we have to renumber Vars in its child nodes
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* and append the modified subquery rangetable to the outer rangetable.
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* Therefore "rtable" is an in/out argument and really should be declared
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* "List **". But in the interest of notational simplicity we don't do that.
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* (Since rtable can't be NIL if there's a SubqueryScan, the list header
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* address won't change when we append a subquery rangetable.)
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*/
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Plan *
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set_plan_references(Plan *plan, List *rtable)
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{
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ListCell *l;
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if (plan == NULL)
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return NULL;
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/*
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* Plan-type-specific fixes
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*/
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switch (nodeTag(plan))
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{
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case T_SeqScan:
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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break;
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case T_IndexScan:
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan,
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(Node *) ((IndexScan *) plan)->indexqual);
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fix_expr_references(plan,
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(Node *) ((IndexScan *) plan)->indexqualorig);
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break;
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case T_BitmapIndexScan:
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/* no need to fix targetlist and qual */
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Assert(plan->targetlist == NIL);
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Assert(plan->qual == NIL);
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fix_expr_references(plan,
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(Node *) ((BitmapIndexScan *) plan)->indexqual);
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fix_expr_references(plan,
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(Node *) ((BitmapIndexScan *) plan)->indexqualorig);
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break;
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case T_BitmapHeapScan:
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan,
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(Node *) ((BitmapHeapScan *) plan)->bitmapqualorig);
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break;
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case T_TidScan:
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan, (Node *) ((TidScan *) plan)->tidquals);
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break;
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case T_SubqueryScan:
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/* Needs special treatment, see comments below */
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return set_subqueryscan_references((SubqueryScan *) plan, rtable);
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case T_FunctionScan:
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{
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RangeTblEntry *rte;
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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rte = rt_fetch(((FunctionScan *) plan)->scan.scanrelid,
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rtable);
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Assert(rte->rtekind == RTE_FUNCTION);
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fix_expr_references(plan, rte->funcexpr);
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}
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break;
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case T_ValuesScan:
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{
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RangeTblEntry *rte;
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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rte = rt_fetch(((ValuesScan *) plan)->scan.scanrelid,
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rtable);
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Assert(rte->rtekind == RTE_VALUES);
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fix_expr_references(plan, (Node *) rte->values_lists);
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}
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break;
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case T_NestLoop:
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set_join_references((Join *) plan);
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan, (Node *) ((Join *) plan)->joinqual);
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break;
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case T_MergeJoin:
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set_join_references((Join *) plan);
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan, (Node *) ((Join *) plan)->joinqual);
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fix_expr_references(plan,
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(Node *) ((MergeJoin *) plan)->mergeclauses);
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break;
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case T_HashJoin:
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set_join_references((Join *) plan);
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan, (Node *) ((Join *) plan)->joinqual);
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fix_expr_references(plan,
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(Node *) ((HashJoin *) plan)->hashclauses);
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break;
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case T_Hash:
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case T_Material:
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case T_Sort:
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case T_Unique:
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case T_SetOp:
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/*
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* These plan types don't actually bother to evaluate their
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* targetlists (because they just return their unmodified input
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* tuples). The optimizer is lazy about creating really valid
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* targetlists for them --- it tends to just put in a pointer to
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* the child plan node's tlist. Hence, we leave the tlist alone.
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* In particular, we do not want to process subplans in the tlist,
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* since we will likely end up reprocessing subplans that also
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* appear in lower levels of the plan tree!
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*
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* Since these plan types don't check quals either, we should not
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* find any qual expression attached to them.
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*/
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Assert(plan->qual == NIL);
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break;
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case T_Limit:
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/*
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* Like the plan types above, Limit doesn't evaluate its tlist or
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* quals. It does have live expressions for limit/offset,
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* however.
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*/
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Assert(plan->qual == NIL);
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fix_expr_references(plan, ((Limit *) plan)->limitOffset);
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fix_expr_references(plan, ((Limit *) plan)->limitCount);
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break;
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case T_Agg:
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case T_Group:
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set_uppernode_references(plan, (Index) 0);
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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break;
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case T_Result:
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/*
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* Result may or may not have a subplan; no need to fix up subplan
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* references if it hasn't got one...
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*
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* XXX why does Result use a different subvarno from Agg/Group?
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*/
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if (plan->lefttree != NULL)
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set_uppernode_references(plan, (Index) OUTER);
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fix_expr_references(plan, (Node *) plan->targetlist);
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fix_expr_references(plan, (Node *) plan->qual);
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fix_expr_references(plan, ((Result *) plan)->resconstantqual);
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break;
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case T_Append:
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/*
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* Append, like Sort et al, doesn't actually evaluate its
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* targetlist or check quals, and we haven't bothered to give it
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* its own tlist copy. So, don't fix targetlist/qual. But do
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* recurse into child plans.
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*/
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Assert(plan->qual == NIL);
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foreach(l, ((Append *) plan)->appendplans)
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lfirst(l) = set_plan_references((Plan *) lfirst(l), rtable);
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break;
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case T_BitmapAnd:
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/* BitmapAnd works like Append, but has no tlist */
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Assert(plan->targetlist == NIL);
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Assert(plan->qual == NIL);
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foreach(l, ((BitmapAnd *) plan)->bitmapplans)
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lfirst(l) = set_plan_references((Plan *) lfirst(l), rtable);
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break;
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case T_BitmapOr:
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/* BitmapOr works like Append, but has no tlist */
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Assert(plan->targetlist == NIL);
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Assert(plan->qual == NIL);
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foreach(l, ((BitmapOr *) plan)->bitmapplans)
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lfirst(l) = set_plan_references((Plan *) lfirst(l), rtable);
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break;
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default:
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elog(ERROR, "unrecognized node type: %d",
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(int) nodeTag(plan));
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break;
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}
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/*
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* Now recurse into child plans and initplans, if any
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*
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* NOTE: it is essential that we recurse into child plans AFTER we set
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* subplan references in this plan's tlist and quals. If we did the
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* reference-adjustments bottom-up, then we would fail to match this
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* plan's var nodes against the already-modified nodes of the children.
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* Fortunately, that consideration doesn't apply to SubPlan nodes; else
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* we'd need two passes over the expression trees.
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*/
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plan->lefttree = set_plan_references(plan->lefttree, rtable);
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plan->righttree = set_plan_references(plan->righttree, rtable);
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foreach(l, plan->initPlan)
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{
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SubPlan *sp = (SubPlan *) lfirst(l);
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Assert(IsA(sp, SubPlan));
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sp->plan = set_plan_references(sp->plan, sp->rtable);
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}
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return plan;
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}
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/*
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* set_subqueryscan_references
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* Do set_plan_references processing on a SubqueryScan
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*
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* We try to strip out the SubqueryScan entirely; if we can't, we have
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* to do the normal processing on it.
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*/
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static Plan *
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set_subqueryscan_references(SubqueryScan *plan, List *rtable)
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{
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Plan *result;
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RangeTblEntry *rte;
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ListCell *l;
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/* First, recursively process the subplan */
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rte = rt_fetch(plan->scan.scanrelid, rtable);
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Assert(rte->rtekind == RTE_SUBQUERY);
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plan->subplan = set_plan_references(plan->subplan,
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rte->subquery->rtable);
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/*
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* We have to process any initplans too; set_plan_references can't do it
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* for us because of the possibility of double-processing.
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*/
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foreach(l, plan->scan.plan.initPlan)
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{
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SubPlan *sp = (SubPlan *) lfirst(l);
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Assert(IsA(sp, SubPlan));
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sp->plan = set_plan_references(sp->plan, sp->rtable);
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}
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if (trivial_subqueryscan(plan))
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{
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/*
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* We can omit the SubqueryScan node and just pull up the subplan. We
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* have to merge its rtable into the outer rtable, which means
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* adjusting varnos throughout the subtree.
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*/
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int rtoffset = list_length(rtable);
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List *sub_rtable;
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ListCell *lp,
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*lc;
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sub_rtable = copyObject(rte->subquery->rtable);
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range_table_walker(sub_rtable,
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adjust_expr_varnos_walker,
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(void *) &rtoffset,
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QTW_IGNORE_RT_SUBQUERIES);
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rtable = list_concat(rtable, sub_rtable);
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/*
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* we have to copy the subplan to make sure there are no duplicately
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* linked nodes in it, else adjust_plan_varnos might increment some
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* varnos twice
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*/
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result = copyObject(plan->subplan);
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adjust_plan_varnos(result, rtoffset);
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result->initPlan = list_concat(plan->scan.plan.initPlan,
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result->initPlan);
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/*
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* We also have to transfer the SubqueryScan's result-column names
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* into the subplan, else columns sent to client will be improperly
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* labeled if this is the topmost plan level. Copy the "source
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* column" information too.
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*/
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forboth(lp, plan->scan.plan.targetlist, lc, result->targetlist)
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{
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TargetEntry *ptle = (TargetEntry *) lfirst(lp);
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TargetEntry *ctle = (TargetEntry *) lfirst(lc);
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ctle->resname = ptle->resname;
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ctle->resorigtbl = ptle->resorigtbl;
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ctle->resorigcol = ptle->resorigcol;
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}
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}
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else
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{
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/*
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* Keep the SubqueryScan node. We have to do the processing that
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* set_plan_references would otherwise have done on it. Notice we do
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* not do set_uppernode_references() here, because a SubqueryScan will
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* always have been created with correct references to its subplan's
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* outputs to begin with.
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*/
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result = (Plan *) plan;
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fix_expr_references(result, (Node *) result->targetlist);
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fix_expr_references(result, (Node *) result->qual);
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}
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return result;
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}
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|
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/*
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* trivial_subqueryscan
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* Detect whether a SubqueryScan can be deleted from the plan tree.
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*
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* We can delete it if it has no qual to check and the targetlist just
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* regurgitates the output of the child plan.
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*/
|
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static bool
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trivial_subqueryscan(SubqueryScan *plan)
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{
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int attrno;
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ListCell *lp,
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*lc;
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if (plan->scan.plan.qual != NIL)
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return false;
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|
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if (list_length(plan->scan.plan.targetlist) !=
|
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list_length(plan->subplan->targetlist))
|
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return false; /* tlists not same length */
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|
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attrno = 1;
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forboth(lp, plan->scan.plan.targetlist, lc, plan->subplan->targetlist)
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{
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TargetEntry *ptle = (TargetEntry *) lfirst(lp);
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TargetEntry *ctle = (TargetEntry *) lfirst(lc);
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|
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if (ptle->resjunk != ctle->resjunk)
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return false; /* tlist doesn't match junk status */
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|
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/*
|
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* We accept either a Var referencing the corresponding element of the
|
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* subplan tlist, or a Const equaling the subplan element. See
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* generate_setop_tlist() for motivation.
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*/
|
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if (ptle->expr && IsA(ptle->expr, Var))
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{
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Var *var = (Var *) ptle->expr;
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Assert(var->varno == plan->scan.scanrelid);
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Assert(var->varlevelsup == 0);
|
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if (var->varattno != attrno)
|
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return false; /* out of order */
|
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}
|
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else if (ptle->expr && IsA(ptle->expr, Const))
|
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{
|
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if (!equal(ptle->expr, ctle->expr))
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return false;
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}
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else
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return false;
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|
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attrno++;
|
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}
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* adjust_plan_varnos
|
|
* Offset varnos and other rangetable indexes in a plan tree by rtoffset.
|
|
*/
|
|
static void
|
|
adjust_plan_varnos(Plan *plan, int rtoffset)
|
|
{
|
|
ListCell *l;
|
|
|
|
if (plan == NULL)
|
|
return;
|
|
|
|
/*
|
|
* Plan-type-specific fixes
|
|
*/
|
|
switch (nodeTag(plan))
|
|
{
|
|
case T_SeqScan:
|
|
((SeqScan *) plan)->scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
break;
|
|
case T_IndexScan:
|
|
((IndexScan *) plan)->scan.scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((IndexScan *) plan)->indexqual,
|
|
rtoffset);
|
|
adjust_expr_varnos((Node *) ((IndexScan *) plan)->indexqualorig,
|
|
rtoffset);
|
|
break;
|
|
case T_BitmapIndexScan:
|
|
((BitmapIndexScan *) plan)->scan.scanrelid += rtoffset;
|
|
/* no need to fix targetlist and qual */
|
|
Assert(plan->targetlist == NIL);
|
|
Assert(plan->qual == NIL);
|
|
adjust_expr_varnos((Node *) ((BitmapIndexScan *) plan)->indexqual,
|
|
rtoffset);
|
|
adjust_expr_varnos((Node *) ((BitmapIndexScan *) plan)->indexqualorig,
|
|
rtoffset);
|
|
break;
|
|
case T_BitmapHeapScan:
|
|
((BitmapHeapScan *) plan)->scan.scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((BitmapHeapScan *) plan)->bitmapqualorig,
|
|
rtoffset);
|
|
break;
|
|
case T_TidScan:
|
|
((TidScan *) plan)->scan.scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((TidScan *) plan)->tidquals,
|
|
rtoffset);
|
|
break;
|
|
case T_SubqueryScan:
|
|
((SubqueryScan *) plan)->scan.scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
/* we should not recurse into the subquery! */
|
|
break;
|
|
case T_FunctionScan:
|
|
((FunctionScan *) plan)->scan.scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
/* rte was already fixed by set_subqueryscan_references */
|
|
break;
|
|
case T_ValuesScan:
|
|
((ValuesScan *) plan)->scan.scanrelid += rtoffset;
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
/* rte was already fixed by set_subqueryscan_references */
|
|
break;
|
|
case T_NestLoop:
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((Join *) plan)->joinqual, rtoffset);
|
|
break;
|
|
case T_MergeJoin:
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((Join *) plan)->joinqual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((MergeJoin *) plan)->mergeclauses,
|
|
rtoffset);
|
|
break;
|
|
case T_HashJoin:
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((Join *) plan)->joinqual, rtoffset);
|
|
adjust_expr_varnos((Node *) ((HashJoin *) plan)->hashclauses,
|
|
rtoffset);
|
|
break;
|
|
case T_Hash:
|
|
case T_Material:
|
|
case T_Sort:
|
|
case T_Unique:
|
|
case T_SetOp:
|
|
|
|
/*
|
|
* Even though the targetlist won't be used by the executor, we
|
|
* fix it up for possible use by EXPLAIN (not to mention ease of
|
|
* debugging --- wrong varnos are very confusing).
|
|
*/
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
Assert(plan->qual == NIL);
|
|
break;
|
|
case T_Limit:
|
|
|
|
/*
|
|
* Like the plan types above, Limit doesn't evaluate its tlist or
|
|
* quals. It does have live expressions for limit/offset,
|
|
* however.
|
|
*/
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
Assert(plan->qual == NIL);
|
|
adjust_expr_varnos(((Limit *) plan)->limitOffset, rtoffset);
|
|
adjust_expr_varnos(((Limit *) plan)->limitCount, rtoffset);
|
|
break;
|
|
case T_Agg:
|
|
case T_Group:
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
break;
|
|
case T_Result:
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
adjust_expr_varnos((Node *) plan->qual, rtoffset);
|
|
adjust_expr_varnos(((Result *) plan)->resconstantqual, rtoffset);
|
|
break;
|
|
case T_Append:
|
|
adjust_expr_varnos((Node *) plan->targetlist, rtoffset);
|
|
Assert(plan->qual == NIL);
|
|
foreach(l, ((Append *) plan)->appendplans)
|
|
adjust_plan_varnos((Plan *) lfirst(l), rtoffset);
|
|
break;
|
|
case T_BitmapAnd:
|
|
/* BitmapAnd works like Append, but has no tlist */
|
|
Assert(plan->targetlist == NIL);
|
|
Assert(plan->qual == NIL);
|
|
foreach(l, ((BitmapAnd *) plan)->bitmapplans)
|
|
adjust_plan_varnos((Plan *) lfirst(l), rtoffset);
|
|
break;
|
|
case T_BitmapOr:
|
|
/* BitmapOr works like Append, but has no tlist */
|
|
Assert(plan->targetlist == NIL);
|
|
Assert(plan->qual == NIL);
|
|
foreach(l, ((BitmapOr *) plan)->bitmapplans)
|
|
adjust_plan_varnos((Plan *) lfirst(l), rtoffset);
|
|
break;
|
|
default:
|
|
elog(ERROR, "unrecognized node type: %d",
|
|
(int) nodeTag(plan));
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Now recurse into child plans.
|
|
*
|
|
* We don't need to (and in fact mustn't) recurse into subqueries, so no
|
|
* need to examine initPlan list.
|
|
*/
|
|
adjust_plan_varnos(plan->lefttree, rtoffset);
|
|
adjust_plan_varnos(plan->righttree, rtoffset);
|
|
}
|
|
|
|
/*
|
|
* adjust_expr_varnos
|
|
* Offset varnos of Vars in an expression by rtoffset.
|
|
*
|
|
* This is different from the rewriter's OffsetVarNodes in that it has to
|
|
* work on an already-planned expression tree; in particular, we should not
|
|
* disturb INNER and OUTER references. On the other hand, we don't have to
|
|
* recurse into subqueries nor deal with outer-level Vars, so it's pretty
|
|
* simple.
|
|
*/
|
|
static void
|
|
adjust_expr_varnos(Node *node, int rtoffset)
|
|
{
|
|
/* This tree walk requires no special setup, so away we go... */
|
|
adjust_expr_varnos_walker(node, &rtoffset);
|
|
}
|
|
|
|
static bool
|
|
adjust_expr_varnos_walker(Node *node, int *context)
|
|
{
|
|
if (node == NULL)
|
|
return false;
|
|
if (IsA(node, Var))
|
|
{
|
|
Var *var = (Var *) node;
|
|
|
|
Assert(var->varlevelsup == 0);
|
|
if (var->varno > 0 && var->varno != INNER && var->varno != OUTER)
|
|
var->varno += *context;
|
|
if (var->varnoold > 0)
|
|
var->varnoold += *context;
|
|
return false;
|
|
}
|
|
return expression_tree_walker(node, adjust_expr_varnos_walker,
|
|
(void *) context);
|
|
}
|
|
|
|
/*
|
|
* fix_expr_references
|
|
* Do final cleanup on expressions (targetlists or quals).
|
|
*
|
|
* This consists of looking up operator opcode info for OpExpr nodes
|
|
* and recursively performing set_plan_references on subplans.
|
|
*
|
|
* The Plan argument is currently unused, but might be needed again someday.
|
|
*/
|
|
static void
|
|
fix_expr_references(Plan *plan, Node *node)
|
|
{
|
|
/* This tree walk requires no special setup, so away we go... */
|
|
fix_expr_references_walker(node, NULL);
|
|
}
|
|
|
|
static bool
|
|
fix_expr_references_walker(Node *node, void *context)
|
|
{
|
|
if (node == NULL)
|
|
return false;
|
|
if (IsA(node, OpExpr))
|
|
set_opfuncid((OpExpr *) node);
|
|
else if (IsA(node, DistinctExpr))
|
|
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
|
|
else if (IsA(node, ScalarArrayOpExpr))
|
|
set_sa_opfuncid((ScalarArrayOpExpr *) node);
|
|
else if (IsA(node, NullIfExpr))
|
|
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
|
|
else if (IsA(node, SubPlan))
|
|
{
|
|
SubPlan *sp = (SubPlan *) node;
|
|
|
|
sp->plan = set_plan_references(sp->plan, sp->rtable);
|
|
}
|
|
return expression_tree_walker(node, fix_expr_references_walker, context);
|
|
}
|
|
|
|
/*
|
|
* set_join_references
|
|
* Modifies the target list and quals of a join node to reference its
|
|
* subplans, by setting the varnos to OUTER or INNER and setting attno
|
|
* values to the result domain number of either the corresponding outer
|
|
* or inner join tuple item.
|
|
*
|
|
* In the case of a nestloop with inner indexscan, we will also need to
|
|
* apply the same transformation to any outer vars appearing in the
|
|
* quals of the child indexscan. set_inner_join_references does that.
|
|
*
|
|
* 'join' is a join plan node
|
|
*/
|
|
static void
|
|
set_join_references(Join *join)
|
|
{
|
|
Plan *outer_plan = join->plan.lefttree;
|
|
Plan *inner_plan = join->plan.righttree;
|
|
indexed_tlist *outer_itlist;
|
|
indexed_tlist *inner_itlist;
|
|
|
|
outer_itlist = build_tlist_index(outer_plan->targetlist);
|
|
inner_itlist = build_tlist_index(inner_plan->targetlist);
|
|
|
|
/* All join plans have tlist, qual, and joinqual */
|
|
join->plan.targetlist = join_references(join->plan.targetlist,
|
|
outer_itlist,
|
|
inner_itlist,
|
|
(Index) 0);
|
|
join->plan.qual = join_references(join->plan.qual,
|
|
outer_itlist,
|
|
inner_itlist,
|
|
(Index) 0);
|
|
join->joinqual = join_references(join->joinqual,
|
|
outer_itlist,
|
|
inner_itlist,
|
|
(Index) 0);
|
|
|
|
/* Now do join-type-specific stuff */
|
|
if (IsA(join, NestLoop))
|
|
{
|
|
/* This processing is split out to handle possible recursion */
|
|
set_inner_join_references(inner_plan,
|
|
outer_itlist);
|
|
}
|
|
else if (IsA(join, MergeJoin))
|
|
{
|
|
MergeJoin *mj = (MergeJoin *) join;
|
|
|
|
mj->mergeclauses = join_references(mj->mergeclauses,
|
|
outer_itlist,
|
|
inner_itlist,
|
|
(Index) 0);
|
|
}
|
|
else if (IsA(join, HashJoin))
|
|
{
|
|
HashJoin *hj = (HashJoin *) join;
|
|
|
|
hj->hashclauses = join_references(hj->hashclauses,
|
|
outer_itlist,
|
|
inner_itlist,
|
|
(Index) 0);
|
|
}
|
|
|
|
pfree(outer_itlist);
|
|
pfree(inner_itlist);
|
|
}
|
|
|
|
/*
|
|
* set_inner_join_references
|
|
* Handle join references appearing in an inner indexscan's quals
|
|
*
|
|
* To handle bitmap-scan plan trees, we have to be able to recurse down
|
|
* to the bottom BitmapIndexScan nodes; likewise, appendrel indexscans
|
|
* require recursing through Append nodes. This is split out as a separate
|
|
* function so that it can recurse.
|
|
*/
|
|
static void
|
|
set_inner_join_references(Plan *inner_plan, indexed_tlist *outer_itlist)
|
|
{
|
|
if (IsA(inner_plan, IndexScan))
|
|
{
|
|
/*
|
|
* An index is being used to reduce the number of tuples scanned in
|
|
* the inner relation. If there are join clauses being used with the
|
|
* index, we must update their outer-rel var nodes to refer to the
|
|
* outer side of the join.
|
|
*/
|
|
IndexScan *innerscan = (IndexScan *) inner_plan;
|
|
List *indexqualorig = innerscan->indexqualorig;
|
|
|
|
/* No work needed if indexqual refers only to its own rel... */
|
|
if (NumRelids((Node *) indexqualorig) > 1)
|
|
{
|
|
Index innerrel = innerscan->scan.scanrelid;
|
|
|
|
/* only refs to outer vars get changed in the inner qual */
|
|
innerscan->indexqualorig = join_references(indexqualorig,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
innerscan->indexqual = join_references(innerscan->indexqual,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
|
|
/*
|
|
* We must fix the inner qpqual too, if it has join clauses (this
|
|
* could happen if special operators are involved: some indexquals
|
|
* may get rechecked as qpquals).
|
|
*/
|
|
if (NumRelids((Node *) inner_plan->qual) > 1)
|
|
inner_plan->qual = join_references(inner_plan->qual,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
}
|
|
}
|
|
else if (IsA(inner_plan, BitmapIndexScan))
|
|
{
|
|
/*
|
|
* Same, but index is being used within a bitmap plan.
|
|
*/
|
|
BitmapIndexScan *innerscan = (BitmapIndexScan *) inner_plan;
|
|
List *indexqualorig = innerscan->indexqualorig;
|
|
|
|
/* No work needed if indexqual refers only to its own rel... */
|
|
if (NumRelids((Node *) indexqualorig) > 1)
|
|
{
|
|
Index innerrel = innerscan->scan.scanrelid;
|
|
|
|
/* only refs to outer vars get changed in the inner qual */
|
|
innerscan->indexqualorig = join_references(indexqualorig,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
innerscan->indexqual = join_references(innerscan->indexqual,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
/* no need to fix inner qpqual */
|
|
Assert(inner_plan->qual == NIL);
|
|
}
|
|
}
|
|
else if (IsA(inner_plan, BitmapHeapScan))
|
|
{
|
|
/*
|
|
* The inner side is a bitmap scan plan. Fix the top node, and
|
|
* recurse to get the lower nodes.
|
|
*
|
|
* Note: create_bitmap_scan_plan removes clauses from bitmapqualorig
|
|
* if they are duplicated in qpqual, so must test these independently.
|
|
*/
|
|
BitmapHeapScan *innerscan = (BitmapHeapScan *) inner_plan;
|
|
Index innerrel = innerscan->scan.scanrelid;
|
|
List *bitmapqualorig = innerscan->bitmapqualorig;
|
|
|
|
/* only refs to outer vars get changed in the inner qual */
|
|
if (NumRelids((Node *) bitmapqualorig) > 1)
|
|
innerscan->bitmapqualorig = join_references(bitmapqualorig,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
|
|
/*
|
|
* We must fix the inner qpqual too, if it has join clauses (this
|
|
* could happen if special operators are involved: some indexquals may
|
|
* get rechecked as qpquals).
|
|
*/
|
|
if (NumRelids((Node *) inner_plan->qual) > 1)
|
|
inner_plan->qual = join_references(inner_plan->qual,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
|
|
/* Now recurse */
|
|
set_inner_join_references(inner_plan->lefttree,
|
|
outer_itlist);
|
|
}
|
|
else if (IsA(inner_plan, BitmapAnd))
|
|
{
|
|
/* All we need do here is recurse */
|
|
BitmapAnd *innerscan = (BitmapAnd *) inner_plan;
|
|
ListCell *l;
|
|
|
|
foreach(l, innerscan->bitmapplans)
|
|
{
|
|
set_inner_join_references((Plan *) lfirst(l),
|
|
outer_itlist);
|
|
}
|
|
}
|
|
else if (IsA(inner_plan, BitmapOr))
|
|
{
|
|
/* All we need do here is recurse */
|
|
BitmapOr *innerscan = (BitmapOr *) inner_plan;
|
|
ListCell *l;
|
|
|
|
foreach(l, innerscan->bitmapplans)
|
|
{
|
|
set_inner_join_references((Plan *) lfirst(l),
|
|
outer_itlist);
|
|
}
|
|
}
|
|
else if (IsA(inner_plan, Append))
|
|
{
|
|
/*
|
|
* The inner side is an append plan. Recurse to see if it contains
|
|
* indexscans that need to be fixed.
|
|
*/
|
|
Append *appendplan = (Append *) inner_plan;
|
|
ListCell *l;
|
|
|
|
foreach(l, appendplan->appendplans)
|
|
{
|
|
set_inner_join_references((Plan *) lfirst(l),
|
|
outer_itlist);
|
|
}
|
|
}
|
|
else if (IsA(inner_plan, TidScan))
|
|
{
|
|
TidScan *innerscan = (TidScan *) inner_plan;
|
|
Index innerrel = innerscan->scan.scanrelid;
|
|
|
|
innerscan->tidquals = join_references(innerscan->tidquals,
|
|
outer_itlist,
|
|
NULL,
|
|
innerrel);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* set_uppernode_references
|
|
* Update the targetlist and quals of an upper-level plan node
|
|
* to refer to the tuples returned by its lefttree subplan.
|
|
*
|
|
* This is used for single-input plan types like Agg, Group, Result.
|
|
*
|
|
* In most cases, we have to match up individual Vars in the tlist and
|
|
* qual expressions with elements of the subplan's tlist (which was
|
|
* generated by flatten_tlist() from these selfsame expressions, so it
|
|
* should have all the required variables). There is an important exception,
|
|
* however: GROUP BY and ORDER BY expressions will have been pushed into the
|
|
* subplan tlist unflattened. If these values are also needed in the output
|
|
* then we want to reference the subplan tlist element rather than recomputing
|
|
* the expression.
|
|
*/
|
|
static void
|
|
set_uppernode_references(Plan *plan, Index subvarno)
|
|
{
|
|
Plan *subplan = plan->lefttree;
|
|
indexed_tlist *subplan_itlist;
|
|
List *output_targetlist;
|
|
ListCell *l;
|
|
|
|
if (subplan != NULL)
|
|
subplan_itlist = build_tlist_index(subplan->targetlist);
|
|
else
|
|
subplan_itlist = build_tlist_index(NIL);
|
|
|
|
output_targetlist = NIL;
|
|
foreach(l, plan->targetlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(l);
|
|
Node *newexpr;
|
|
|
|
newexpr = replace_vars_with_subplan_refs((Node *) tle->expr,
|
|
subplan_itlist,
|
|
subvarno);
|
|
tle = flatCopyTargetEntry(tle);
|
|
tle->expr = (Expr *) newexpr;
|
|
output_targetlist = lappend(output_targetlist, tle);
|
|
}
|
|
plan->targetlist = output_targetlist;
|
|
|
|
plan->qual = (List *)
|
|
replace_vars_with_subplan_refs((Node *) plan->qual,
|
|
subplan_itlist,
|
|
subvarno);
|
|
|
|
pfree(subplan_itlist);
|
|
}
|
|
|
|
/*
|
|
* build_tlist_index --- build an index data structure for a child tlist
|
|
*
|
|
* In most cases, subplan tlists will be "flat" tlists with only Vars,
|
|
* so we try to optimize that case by extracting information about Vars
|
|
* in advance. Matching a parent tlist to a child is still an O(N^2)
|
|
* operation, but at least with a much smaller constant factor than plain
|
|
* tlist_member() searches.
|
|
*
|
|
* The result of this function is an indexed_tlist struct to pass to
|
|
* search_indexed_tlist_for_var() or search_indexed_tlist_for_non_var().
|
|
* When done, the indexed_tlist may be freed with a single pfree().
|
|
*/
|
|
static indexed_tlist *
|
|
build_tlist_index(List *tlist)
|
|
{
|
|
indexed_tlist *itlist;
|
|
tlist_vinfo *vinfo;
|
|
ListCell *l;
|
|
|
|
/* Create data structure with enough slots for all tlist entries */
|
|
itlist = (indexed_tlist *)
|
|
palloc(offsetof(indexed_tlist, vars) +
|
|
list_length(tlist) * sizeof(tlist_vinfo));
|
|
|
|
itlist->tlist = tlist;
|
|
itlist->has_non_vars = false;
|
|
|
|
/* Find the Vars and fill in the index array */
|
|
vinfo = itlist->vars;
|
|
foreach(l, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(l);
|
|
|
|
if (tle->expr && IsA(tle->expr, Var))
|
|
{
|
|
Var *var = (Var *) tle->expr;
|
|
|
|
vinfo->varno = var->varno;
|
|
vinfo->varattno = var->varattno;
|
|
vinfo->resno = tle->resno;
|
|
vinfo++;
|
|
}
|
|
else
|
|
itlist->has_non_vars = true;
|
|
}
|
|
|
|
itlist->num_vars = (vinfo - itlist->vars);
|
|
|
|
return itlist;
|
|
}
|
|
|
|
/*
|
|
* build_tlist_index_other_vars --- build a restricted tlist index
|
|
*
|
|
* This is like build_tlist_index, but we only index tlist entries that
|
|
* are Vars and belong to some rel other than the one specified.
|
|
*/
|
|
static indexed_tlist *
|
|
build_tlist_index_other_vars(List *tlist, Index ignore_rel)
|
|
{
|
|
indexed_tlist *itlist;
|
|
tlist_vinfo *vinfo;
|
|
ListCell *l;
|
|
|
|
/* Create data structure with enough slots for all tlist entries */
|
|
itlist = (indexed_tlist *)
|
|
palloc(offsetof(indexed_tlist, vars) +
|
|
list_length(tlist) * sizeof(tlist_vinfo));
|
|
|
|
itlist->tlist = tlist;
|
|
itlist->has_non_vars = false;
|
|
|
|
/* Find the desired Vars and fill in the index array */
|
|
vinfo = itlist->vars;
|
|
foreach(l, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(l);
|
|
|
|
if (tle->expr && IsA(tle->expr, Var))
|
|
{
|
|
Var *var = (Var *) tle->expr;
|
|
|
|
if (var->varno != ignore_rel)
|
|
{
|
|
vinfo->varno = var->varno;
|
|
vinfo->varattno = var->varattno;
|
|
vinfo->resno = tle->resno;
|
|
vinfo++;
|
|
}
|
|
}
|
|
}
|
|
|
|
itlist->num_vars = (vinfo - itlist->vars);
|
|
|
|
return itlist;
|
|
}
|
|
|
|
/*
|
|
* search_indexed_tlist_for_var --- find a Var in an indexed tlist
|
|
*
|
|
* If a match is found, return a copy of the given Var with suitably
|
|
* modified varno/varattno (to wit, newvarno and the resno of the TLE entry).
|
|
* If no match, return NULL.
|
|
*/
|
|
static Var *
|
|
search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist, Index newvarno)
|
|
{
|
|
Index varno = var->varno;
|
|
AttrNumber varattno = var->varattno;
|
|
tlist_vinfo *vinfo;
|
|
int i;
|
|
|
|
vinfo = itlist->vars;
|
|
i = itlist->num_vars;
|
|
while (i-- > 0)
|
|
{
|
|
if (vinfo->varno == varno && vinfo->varattno == varattno)
|
|
{
|
|
/* Found a match */
|
|
Var *newvar = (Var *) copyObject(var);
|
|
|
|
newvar->varno = newvarno;
|
|
newvar->varattno = vinfo->resno;
|
|
return newvar;
|
|
}
|
|
vinfo++;
|
|
}
|
|
return NULL; /* no match */
|
|
}
|
|
|
|
/*
|
|
* search_indexed_tlist_for_non_var --- find a non-Var in an indexed tlist
|
|
*
|
|
* If a match is found, return a Var constructed to reference the tlist item.
|
|
* If no match, return NULL.
|
|
*
|
|
* NOTE: it is a waste of time to call this if !itlist->has_non_vars
|
|
*/
|
|
static Var *
|
|
search_indexed_tlist_for_non_var(Node *node,
|
|
indexed_tlist *itlist, Index newvarno)
|
|
{
|
|
TargetEntry *tle;
|
|
|
|
tle = tlist_member(node, itlist->tlist);
|
|
if (tle)
|
|
{
|
|
/* Found a matching subplan output expression */
|
|
Var *newvar;
|
|
|
|
newvar = makeVar(newvarno,
|
|
tle->resno,
|
|
exprType((Node *) tle->expr),
|
|
exprTypmod((Node *) tle->expr),
|
|
0);
|
|
newvar->varnoold = 0; /* wasn't ever a plain Var */
|
|
newvar->varoattno = 0;
|
|
return newvar;
|
|
}
|
|
return NULL; /* no match */
|
|
}
|
|
|
|
/*
|
|
* join_references
|
|
* Creates a new set of targetlist entries or join qual clauses by
|
|
* changing the varno/varattno values of variables in the clauses
|
|
* to reference target list values from the outer and inner join
|
|
* relation target lists.
|
|
*
|
|
* This is used in two different scenarios: a normal join clause, where
|
|
* all the Vars in the clause *must* be replaced by OUTER or INNER references;
|
|
* and an indexscan being used on the inner side of a nestloop join.
|
|
* In the latter case we want to replace the outer-relation Vars by OUTER
|
|
* references, but not touch the Vars of the inner relation. (We also
|
|
* implement RETURNING clause fixup using this second scenario.)
|
|
*
|
|
* For a normal join, acceptable_rel should be zero so that any failure to
|
|
* match a Var will be reported as an error. For the indexscan case,
|
|
* pass inner_itlist = NULL and acceptable_rel = the ID of the inner relation.
|
|
*
|
|
* 'clauses' is the targetlist or list of join clauses
|
|
* 'outer_itlist' is the indexed target list of the outer join relation
|
|
* 'inner_itlist' is the indexed target list of the inner join relation,
|
|
* or NULL
|
|
* 'acceptable_rel' is either zero or the rangetable index of a relation
|
|
* whose Vars may appear in the clause without provoking an error.
|
|
*
|
|
* Returns the new expression tree. The original clause structure is
|
|
* not modified.
|
|
*/
|
|
static List *
|
|
join_references(List *clauses,
|
|
indexed_tlist *outer_itlist,
|
|
indexed_tlist *inner_itlist,
|
|
Index acceptable_rel)
|
|
{
|
|
join_references_context context;
|
|
|
|
context.outer_itlist = outer_itlist;
|
|
context.inner_itlist = inner_itlist;
|
|
context.acceptable_rel = acceptable_rel;
|
|
return (List *) join_references_mutator((Node *) clauses, &context);
|
|
}
|
|
|
|
static Node *
|
|
join_references_mutator(Node *node,
|
|
join_references_context *context)
|
|
{
|
|
Var *newvar;
|
|
|
|
if (node == NULL)
|
|
return NULL;
|
|
if (IsA(node, Var))
|
|
{
|
|
Var *var = (Var *) node;
|
|
|
|
/* First look for the var in the input tlists */
|
|
newvar = search_indexed_tlist_for_var(var,
|
|
context->outer_itlist,
|
|
OUTER);
|
|
if (newvar)
|
|
return (Node *) newvar;
|
|
if (context->inner_itlist)
|
|
{
|
|
newvar = search_indexed_tlist_for_var(var,
|
|
context->inner_itlist,
|
|
INNER);
|
|
if (newvar)
|
|
return (Node *) newvar;
|
|
}
|
|
|
|
/* Return the Var unmodified, if it's for acceptable_rel */
|
|
if (var->varno == context->acceptable_rel)
|
|
return (Node *) copyObject(var);
|
|
|
|
/* No referent found for Var */
|
|
elog(ERROR, "variable not found in subplan target lists");
|
|
}
|
|
/* Try matching more complex expressions too, if tlists have any */
|
|
if (context->outer_itlist->has_non_vars)
|
|
{
|
|
newvar = search_indexed_tlist_for_non_var(node,
|
|
context->outer_itlist,
|
|
OUTER);
|
|
if (newvar)
|
|
return (Node *) newvar;
|
|
}
|
|
if (context->inner_itlist && context->inner_itlist->has_non_vars)
|
|
{
|
|
newvar = search_indexed_tlist_for_non_var(node,
|
|
context->inner_itlist,
|
|
INNER);
|
|
if (newvar)
|
|
return (Node *) newvar;
|
|
}
|
|
return expression_tree_mutator(node,
|
|
join_references_mutator,
|
|
(void *) context);
|
|
}
|
|
|
|
/*
|
|
* replace_vars_with_subplan_refs
|
|
* This routine modifies an expression tree so that all Var nodes
|
|
* reference target nodes of a subplan. It is used to fix up
|
|
* target and qual expressions of non-join upper-level plan nodes.
|
|
*
|
|
* An error is raised if no matching var can be found in the subplan tlist
|
|
* --- so this routine should only be applied to nodes whose subplans'
|
|
* targetlists were generated via flatten_tlist() or some such method.
|
|
*
|
|
* If itlist->has_non_vars is true, then we try to match whole subexpressions
|
|
* against elements of the subplan tlist, so that we can avoid recomputing
|
|
* expressions that were already computed by the subplan. (This is relatively
|
|
* expensive, so we don't want to try it in the common case where the
|
|
* subplan tlist is just a flattened list of Vars.)
|
|
*
|
|
* 'node': the tree to be fixed (a target item or qual)
|
|
* 'subplan_itlist': indexed target list for subplan
|
|
* 'subvarno': varno to be assigned to all Vars
|
|
*
|
|
* The resulting tree is a copy of the original in which all Var nodes have
|
|
* varno = subvarno, varattno = resno of corresponding subplan target.
|
|
* The original tree is not modified.
|
|
*/
|
|
static Node *
|
|
replace_vars_with_subplan_refs(Node *node,
|
|
indexed_tlist *subplan_itlist,
|
|
Index subvarno)
|
|
{
|
|
replace_vars_with_subplan_refs_context context;
|
|
|
|
context.subplan_itlist = subplan_itlist;
|
|
context.subvarno = subvarno;
|
|
return replace_vars_with_subplan_refs_mutator(node, &context);
|
|
}
|
|
|
|
static Node *
|
|
replace_vars_with_subplan_refs_mutator(Node *node,
|
|
replace_vars_with_subplan_refs_context *context)
|
|
{
|
|
Var *newvar;
|
|
|
|
if (node == NULL)
|
|
return NULL;
|
|
if (IsA(node, Var))
|
|
{
|
|
Var *var = (Var *) node;
|
|
|
|
newvar = search_indexed_tlist_for_var(var,
|
|
context->subplan_itlist,
|
|
context->subvarno);
|
|
if (!newvar)
|
|
elog(ERROR, "variable not found in subplan target list");
|
|
return (Node *) newvar;
|
|
}
|
|
/* Try matching more complex expressions too, if tlist has any */
|
|
if (context->subplan_itlist->has_non_vars)
|
|
{
|
|
newvar = search_indexed_tlist_for_non_var(node,
|
|
context->subplan_itlist,
|
|
context->subvarno);
|
|
if (newvar)
|
|
return (Node *) newvar;
|
|
}
|
|
return expression_tree_mutator(node,
|
|
replace_vars_with_subplan_refs_mutator,
|
|
(void *) context);
|
|
}
|
|
|
|
/*
|
|
* set_returning_clause_references
|
|
* Perform setrefs.c's work on a RETURNING targetlist
|
|
*
|
|
* If the query involves more than just the result table, we have to
|
|
* adjust any Vars that refer to other tables to reference junk tlist
|
|
* entries in the top plan's targetlist. Vars referencing the result
|
|
* table should be left alone, however (the executor will evaluate them
|
|
* using the actual heap tuple, after firing triggers if any). In the
|
|
* adjusted RETURNING list, result-table Vars will still have their
|
|
* original varno, but Vars for other rels will have varno OUTER.
|
|
*
|
|
* We also must apply fix_expr_references to the list.
|
|
*
|
|
* 'rlist': the RETURNING targetlist to be fixed
|
|
* 'topplan': the top Plan node for the query (not yet passed through
|
|
* set_plan_references)
|
|
* 'resultRelation': RT index of the query's result relation
|
|
*/
|
|
List *
|
|
set_returning_clause_references(List *rlist,
|
|
Plan *topplan,
|
|
Index resultRelation)
|
|
{
|
|
indexed_tlist *itlist;
|
|
|
|
/*
|
|
* We can perform the desired Var fixup by abusing the join_references
|
|
* machinery that normally handles inner indexscan fixup. We search the
|
|
* top plan's targetlist for Vars of non-result relations, and use
|
|
* join_references to convert RETURNING Vars into references to those
|
|
* tlist entries, while leaving result-rel Vars as-is.
|
|
*/
|
|
itlist = build_tlist_index_other_vars(topplan->targetlist, resultRelation);
|
|
|
|
rlist = join_references(rlist,
|
|
itlist,
|
|
NULL,
|
|
resultRelation);
|
|
|
|
fix_expr_references(topplan, (Node *) rlist);
|
|
|
|
pfree(itlist);
|
|
|
|
return rlist;
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* OPERATOR REGPROC LOOKUP
|
|
*****************************************************************************/
|
|
|
|
/*
|
|
* fix_opfuncids
|
|
* Calculate opfuncid field from opno for each OpExpr node in given tree.
|
|
* The given tree can be anything expression_tree_walker handles.
|
|
*
|
|
* The argument is modified in-place. (This is OK since we'd want the
|
|
* same change for any node, even if it gets visited more than once due to
|
|
* shared structure.)
|
|
*/
|
|
void
|
|
fix_opfuncids(Node *node)
|
|
{
|
|
/* This tree walk requires no special setup, so away we go... */
|
|
fix_opfuncids_walker(node, NULL);
|
|
}
|
|
|
|
static bool
|
|
fix_opfuncids_walker(Node *node, void *context)
|
|
{
|
|
if (node == NULL)
|
|
return false;
|
|
if (IsA(node, OpExpr))
|
|
set_opfuncid((OpExpr *) node);
|
|
else if (IsA(node, DistinctExpr))
|
|
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
|
|
else if (IsA(node, ScalarArrayOpExpr))
|
|
set_sa_opfuncid((ScalarArrayOpExpr *) node);
|
|
else if (IsA(node, NullIfExpr))
|
|
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
|
|
return expression_tree_walker(node, fix_opfuncids_walker, context);
|
|
}
|
|
|
|
/*
|
|
* set_opfuncid
|
|
* Set the opfuncid (procedure OID) in an OpExpr node,
|
|
* if it hasn't been set already.
|
|
*
|
|
* Because of struct equivalence, this can also be used for
|
|
* DistinctExpr and NullIfExpr nodes.
|
|
*/
|
|
void
|
|
set_opfuncid(OpExpr *opexpr)
|
|
{
|
|
if (opexpr->opfuncid == InvalidOid)
|
|
opexpr->opfuncid = get_opcode(opexpr->opno);
|
|
}
|
|
|
|
/*
|
|
* set_sa_opfuncid
|
|
* As above, for ScalarArrayOpExpr nodes.
|
|
*/
|
|
void
|
|
set_sa_opfuncid(ScalarArrayOpExpr *opexpr)
|
|
{
|
|
if (opexpr->opfuncid == InvalidOid)
|
|
opexpr->opfuncid = get_opcode(opexpr->opno);
|
|
}
|