/*------------------------------------------------------------------------- * * setrefs.c * Post-processing of a completed plan tree: fix references to subplan * vars, compute regproc values for operators, etc * * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/optimizer/plan/setrefs.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/transam.h" #include "catalog/pg_type.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "optimizer/pathnode.h" #include "optimizer/planmain.h" #include "optimizer/planner.h" #include "optimizer/tlist.h" #include "tcop/utility.h" #include "utils/lsyscache.h" #include "utils/syscache.h" typedef struct { Index varno; /* RT index of Var */ AttrNumber varattno; /* attr number of Var */ AttrNumber resno; /* TLE position of Var */ } tlist_vinfo; typedef struct { List *tlist; /* underlying target list */ int num_vars; /* number of plain Var tlist entries */ bool has_ph_vars; /* are there PlaceHolderVar entries? */ bool has_non_vars; /* are there other entries? */ tlist_vinfo vars[FLEXIBLE_ARRAY_MEMBER]; /* has num_vars entries */ } indexed_tlist; typedef struct { PlannerInfo *root; int rtoffset; } fix_scan_expr_context; typedef struct { PlannerInfo *root; indexed_tlist *outer_itlist; indexed_tlist *inner_itlist; Index acceptable_rel; int rtoffset; } fix_join_expr_context; typedef struct { PlannerInfo *root; indexed_tlist *subplan_itlist; Index newvarno; int rtoffset; } fix_upper_expr_context; /* * Check if a Const node is a regclass value. We accept plain OID too, * since a regclass Const will get folded to that type if it's an argument * to oideq or similar operators. (This might result in some extraneous * values in a plan's list of relation dependencies, but the worst result * would be occasional useless replans.) */ #define ISREGCLASSCONST(con) \ (((con)->consttype == REGCLASSOID || (con)->consttype == OIDOID) && \ !(con)->constisnull) #define fix_scan_list(root, lst, rtoffset) \ ((List *) fix_scan_expr(root, (Node *) (lst), rtoffset)) static void add_rtes_to_flat_rtable(PlannerInfo *root, bool recursing); static void flatten_unplanned_rtes(PlannerGlobal *glob, RangeTblEntry *rte); static bool flatten_rtes_walker(Node *node, PlannerGlobal *glob); static void add_rte_to_flat_rtable(PlannerGlobal *glob, RangeTblEntry *rte); static Plan *set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset); static Plan *set_indexonlyscan_references(PlannerInfo *root, IndexOnlyScan *plan, int rtoffset); static Plan *set_subqueryscan_references(PlannerInfo *root, SubqueryScan *plan, int rtoffset); static bool trivial_subqueryscan(SubqueryScan *plan); static Node *fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset); static Node *fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context); static bool fix_scan_expr_walker(Node *node, fix_scan_expr_context *context); static void set_join_references(PlannerInfo *root, Join *join, int rtoffset); static void set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset); static void set_dummy_tlist_references(Plan *plan, int rtoffset); static indexed_tlist *build_tlist_index(List *tlist); static Var *search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist, Index newvarno, int rtoffset); static Var *search_indexed_tlist_for_non_var(Node *node, indexed_tlist *itlist, Index newvarno); static Var *search_indexed_tlist_for_sortgroupref(Node *node, Index sortgroupref, indexed_tlist *itlist, Index newvarno); static List *fix_join_expr(PlannerInfo *root, List *clauses, indexed_tlist *outer_itlist, indexed_tlist *inner_itlist, Index acceptable_rel, int rtoffset); static Node *fix_join_expr_mutator(Node *node, fix_join_expr_context *context); static Node *fix_upper_expr(PlannerInfo *root, Node *node, indexed_tlist *subplan_itlist, Index newvarno, int rtoffset); static Node *fix_upper_expr_mutator(Node *node, fix_upper_expr_context *context); static List *set_returning_clause_references(PlannerInfo *root, List *rlist, Plan *topplan, Index resultRelation, int rtoffset); static bool fix_opfuncids_walker(Node *node, void *context); static bool extract_query_dependencies_walker(Node *node, PlannerInfo *context); /***************************************************************************** * * SUBPLAN REFERENCES * *****************************************************************************/ /* * set_plan_references * * This is the final processing pass of the planner/optimizer. The plan * tree is complete; we just have to adjust some representational details * for the convenience of the executor: * * 1. We flatten the various subquery rangetables into a single list, and * zero out RangeTblEntry fields that are not useful to the executor. * * 2. We adjust Vars in scan nodes to be consistent with the flat rangetable. * * 3. We adjust Vars in upper plan nodes to refer to the outputs of their * subplans. * * 4. PARAM_MULTIEXPR Params are replaced by regular PARAM_EXEC Params, * now that we have finished planning all MULTIEXPR subplans. * * 5. We compute regproc OIDs for operators (ie, we look up the function * that implements each op). * * 6. We create lists of specific objects that the plan depends on. * This will be used by plancache.c to drive invalidation of cached plans. * Relation dependencies are represented by OIDs, and everything else by * PlanInvalItems (this distinction is motivated by the shared-inval APIs). * Currently, relations and user-defined functions are the only types of * objects that are explicitly tracked this way. * * We also perform one final optimization step, which is to delete * SubqueryScan plan nodes that aren't doing anything useful (ie, have * no qual and a no-op targetlist). The reason for doing this last is that * it can't readily be done before set_plan_references, because it would * break set_upper_references: the Vars in the subquery's top tlist * wouldn't match up with the Vars in the outer plan tree. The SubqueryScan * serves a necessary function as a buffer between outer query and subquery * variable numbering ... but after we've flattened the rangetable this is * no longer a problem, since then there's only one rtindex namespace. * * set_plan_references recursively traverses the whole plan tree. * * The return value is normally the same Plan node passed in, but can be * different when the passed-in Plan is a SubqueryScan we decide isn't needed. * * The flattened rangetable entries are appended to root->glob->finalrtable. * Also, rowmarks entries are appended to root->glob->finalrowmarks, and the * RT indexes of ModifyTable result relations to root->glob->resultRelations. * Plan dependencies are appended to root->glob->relationOids (for relations) * and root->glob->invalItems (for everything else). * * Notice that we modify Plan nodes in-place, but use expression_tree_mutator * to process targetlist and qual expressions. We can assume that the Plan * nodes were just built by the planner and are not multiply referenced, but * it's not so safe to assume that for expression tree nodes. */ Plan * set_plan_references(PlannerInfo *root, Plan *plan) { PlannerGlobal *glob = root->glob; int rtoffset = list_length(glob->finalrtable); ListCell *lc; /* * Add all the query's RTEs to the flattened rangetable. The live ones * will have their rangetable indexes increased by rtoffset. (Additional * RTEs, not referenced by the Plan tree, might get added after those.) */ add_rtes_to_flat_rtable(root, false); /* * Adjust RT indexes of PlanRowMarks and add to final rowmarks list */ foreach(lc, root->rowMarks) { PlanRowMark *rc = (PlanRowMark *) lfirst(lc); PlanRowMark *newrc; Assert(IsA(rc, PlanRowMark)); /* flat copy is enough since all fields are scalars */ newrc = (PlanRowMark *) palloc(sizeof(PlanRowMark)); memcpy(newrc, rc, sizeof(PlanRowMark)); /* adjust indexes ... but *not* the rowmarkId */ newrc->rti += rtoffset; newrc->prti += rtoffset; glob->finalrowmarks = lappend(glob->finalrowmarks, newrc); } /* Now fix the Plan tree */ return set_plan_refs(root, plan, rtoffset); } /* * Extract RangeTblEntries from the plan's rangetable, and add to flat rtable * * This can recurse into subquery plans; "recursing" is true if so. */ static void add_rtes_to_flat_rtable(PlannerInfo *root, bool recursing) { PlannerGlobal *glob = root->glob; Index rti; ListCell *lc; /* * Add the query's own RTEs to the flattened rangetable. * * At top level, we must add all RTEs so that their indexes in the * flattened rangetable match up with their original indexes. When * recursing, we only care about extracting relation RTEs. */ foreach(lc, root->parse->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); if (!recursing || rte->rtekind == RTE_RELATION) add_rte_to_flat_rtable(glob, rte); } /* * If there are any dead subqueries, they are not referenced in the Plan * tree, so we must add RTEs contained in them to the flattened rtable * separately. (If we failed to do this, the executor would not perform * expected permission checks for tables mentioned in such subqueries.) * * Note: this pass over the rangetable can't be combined with the previous * one, because that would mess up the numbering of the live RTEs in the * flattened rangetable. */ rti = 1; foreach(lc, root->parse->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); /* * We should ignore inheritance-parent RTEs: their contents have been * pulled up into our rangetable already. Also ignore any subquery * RTEs without matching RelOptInfos, as they likewise have been * pulled up. */ if (rte->rtekind == RTE_SUBQUERY && !rte->inh && rti < root->simple_rel_array_size) { RelOptInfo *rel = root->simple_rel_array[rti]; if (rel != NULL) { Assert(rel->relid == rti); /* sanity check on array */ /* * The subquery might never have been planned at all, if it * was excluded on the basis of self-contradictory constraints * in our query level. In this case apply * flatten_unplanned_rtes. * * If it was planned but the plan is dummy, we assume that it * has been omitted from our plan tree (see * set_subquery_pathlist), and recurse to pull up its RTEs. * * Otherwise, it should be represented by a SubqueryScan node * somewhere in our plan tree, and we'll pull up its RTEs when * we process that plan node. * * However, if we're recursing, then we should pull up RTEs * whether the subplan is dummy or not, because we've found * that some upper query level is treating this one as dummy, * and so we won't scan this level's plan tree at all. */ if (rel->subplan == NULL) flatten_unplanned_rtes(glob, rte); else if (recursing || is_dummy_plan(rel->subplan)) { Assert(rel->subroot != NULL); add_rtes_to_flat_rtable(rel->subroot, true); } } } rti++; } } /* * Extract RangeTblEntries from a subquery that was never planned at all */ static void flatten_unplanned_rtes(PlannerGlobal *glob, RangeTblEntry *rte) { /* Use query_tree_walker to find all RTEs in the parse tree */ (void) query_tree_walker(rte->subquery, flatten_rtes_walker, (void *) glob, QTW_EXAMINE_RTES); } static bool flatten_rtes_walker(Node *node, PlannerGlobal *glob) { if (node == NULL) return false; if (IsA(node, RangeTblEntry)) { RangeTblEntry *rte = (RangeTblEntry *) node; /* As above, we need only save relation RTEs */ if (rte->rtekind == RTE_RELATION) add_rte_to_flat_rtable(glob, rte); return false; } if (IsA(node, Query)) { /* Recurse into subselects */ return query_tree_walker((Query *) node, flatten_rtes_walker, (void *) glob, QTW_EXAMINE_RTES); } return expression_tree_walker(node, flatten_rtes_walker, (void *) glob); } /* * Add (a copy of) the given RTE to the final rangetable * * In the flat rangetable, we zero out substructure pointers that are not * needed by the executor; this reduces the storage space and copying cost * for cached plans. We keep only the alias and eref Alias fields, which * are needed by EXPLAIN, and the selectedCols and modifiedCols bitmaps, * which are needed for executor-startup permissions checking and for * trigger event checking. */ static void add_rte_to_flat_rtable(PlannerGlobal *glob, RangeTblEntry *rte) { RangeTblEntry *newrte; /* flat copy to duplicate all the scalar fields */ newrte = (RangeTblEntry *) palloc(sizeof(RangeTblEntry)); memcpy(newrte, rte, sizeof(RangeTblEntry)); /* zap unneeded sub-structure */ newrte->subquery = NULL; newrte->joinaliasvars = NIL; newrte->functions = NIL; newrte->values_lists = NIL; newrte->values_collations = NIL; newrte->ctecoltypes = NIL; newrte->ctecoltypmods = NIL; newrte->ctecolcollations = NIL; glob->finalrtable = lappend(glob->finalrtable, newrte); /* * Check for RT index overflow; it's very unlikely, but if it did happen, * the executor would get confused by varnos that match the special varno * values. */ if (IS_SPECIAL_VARNO(list_length(glob->finalrtable))) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many range table entries"))); /* * If it's a plain relation RTE, add the table to relationOids. * * We do this even though the RTE might be unreferenced in the plan tree; * this would correspond to cases such as views that were expanded, child * tables that were eliminated by constraint exclusion, etc. Schema * invalidation on such a rel must still force rebuilding of the plan. * * Note we don't bother to avoid making duplicate list entries. We could, * but it would probably cost more cycles than it would save. */ if (newrte->rtekind == RTE_RELATION) glob->relationOids = lappend_oid(glob->relationOids, newrte->relid); } /* * set_plan_refs: recurse through the Plan nodes of a single subquery level */ static Plan * set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset) { ListCell *l; if (plan == NULL) return NULL; /* * Plan-type-specific fixes */ switch (nodeTag(plan)) { case T_SeqScan: { SeqScan *splan = (SeqScan *) plan; splan->scanrelid += rtoffset; splan->plan.targetlist = fix_scan_list(root, splan->plan.targetlist, rtoffset); splan->plan.qual = fix_scan_list(root, splan->plan.qual, rtoffset); } break; case T_IndexScan: { IndexScan *splan = (IndexScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->indexqual = fix_scan_list(root, splan->indexqual, rtoffset); splan->indexqualorig = fix_scan_list(root, splan->indexqualorig, rtoffset); splan->indexorderby = fix_scan_list(root, splan->indexorderby, rtoffset); splan->indexorderbyorig = fix_scan_list(root, splan->indexorderbyorig, rtoffset); } break; case T_IndexOnlyScan: { IndexOnlyScan *splan = (IndexOnlyScan *) plan; return set_indexonlyscan_references(root, splan, rtoffset); } break; case T_BitmapIndexScan: { BitmapIndexScan *splan = (BitmapIndexScan *) plan; splan->scan.scanrelid += rtoffset; /* no need to fix targetlist and qual */ Assert(splan->scan.plan.targetlist == NIL); Assert(splan->scan.plan.qual == NIL); splan->indexqual = fix_scan_list(root, splan->indexqual, rtoffset); splan->indexqualorig = fix_scan_list(root, splan->indexqualorig, rtoffset); } break; case T_BitmapHeapScan: { BitmapHeapScan *splan = (BitmapHeapScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->bitmapqualorig = fix_scan_list(root, splan->bitmapqualorig, rtoffset); } break; case T_TidScan: { TidScan *splan = (TidScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->tidquals = fix_scan_list(root, splan->tidquals, rtoffset); } break; case T_SubqueryScan: /* Needs special treatment, see comments below */ return set_subqueryscan_references(root, (SubqueryScan *) plan, rtoffset); case T_FunctionScan: { FunctionScan *splan = (FunctionScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->functions = fix_scan_list(root, splan->functions, rtoffset); } break; case T_ValuesScan: { ValuesScan *splan = (ValuesScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->values_lists = fix_scan_list(root, splan->values_lists, rtoffset); } break; case T_CteScan: { CteScan *splan = (CteScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); } break; case T_WorkTableScan: { WorkTableScan *splan = (WorkTableScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); } break; case T_ForeignScan: { ForeignScan *splan = (ForeignScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->fdw_exprs = fix_scan_list(root, splan->fdw_exprs, rtoffset); } break; case T_CustomScan: { CustomScan *splan = (CustomScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset); splan->custom_exprs = fix_scan_list(root, splan->custom_exprs, rtoffset); } break; case T_NestLoop: case T_MergeJoin: case T_HashJoin: set_join_references(root, (Join *) plan, rtoffset); break; case T_Hash: case T_Material: case T_Sort: case T_Unique: case T_SetOp: /* * These plan types don't actually bother to evaluate their * targetlists, because they just return their unmodified input * tuples. 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). */ set_dummy_tlist_references(plan, rtoffset); /* * Since these plan types don't check quals either, we should not * find any qual expression attached to them. */ Assert(plan->qual == NIL); break; case T_LockRows: { LockRows *splan = (LockRows *) plan; /* * Like the plan types above, LockRows doesn't evaluate its * tlist or quals. But we have to fix up the RT indexes in * its rowmarks. */ set_dummy_tlist_references(plan, rtoffset); Assert(splan->plan.qual == NIL); foreach(l, splan->rowMarks) { PlanRowMark *rc = (PlanRowMark *) lfirst(l); rc->rti += rtoffset; rc->prti += rtoffset; } } break; case T_Limit: { Limit *splan = (Limit *) plan; /* * Like the plan types above, Limit doesn't evaluate its tlist * or quals. It does have live expressions for limit/offset, * however; and those cannot contain subplan variable refs, so * fix_scan_expr works for them. */ set_dummy_tlist_references(plan, rtoffset); Assert(splan->plan.qual == NIL); splan->limitOffset = fix_scan_expr(root, splan->limitOffset, rtoffset); splan->limitCount = fix_scan_expr(root, splan->limitCount, rtoffset); } break; case T_Agg: case T_Group: set_upper_references(root, plan, rtoffset); break; case T_WindowAgg: { WindowAgg *wplan = (WindowAgg *) plan; set_upper_references(root, plan, rtoffset); /* * Like Limit node limit/offset expressions, WindowAgg has * frame offset expressions, which cannot contain subplan * variable refs, so fix_scan_expr works for them. */ wplan->startOffset = fix_scan_expr(root, wplan->startOffset, rtoffset); wplan->endOffset = fix_scan_expr(root, wplan->endOffset, rtoffset); } break; case T_Result: { Result *splan = (Result *) plan; /* * Result may or may not have a subplan; if not, it's more * like a scan node than an upper node. */ if (splan->plan.lefttree != NULL) set_upper_references(root, plan, rtoffset); else { splan->plan.targetlist = fix_scan_list(root, splan->plan.targetlist, rtoffset); splan->plan.qual = fix_scan_list(root, splan->plan.qual, rtoffset); } /* resconstantqual can't contain any subplan variable refs */ splan->resconstantqual = fix_scan_expr(root, splan->resconstantqual, rtoffset); } break; case T_ModifyTable: { ModifyTable *splan = (ModifyTable *) plan; Assert(splan->plan.targetlist == NIL); Assert(splan->plan.qual == NIL); splan->withCheckOptionLists = fix_scan_list(root, splan->withCheckOptionLists, rtoffset); if (splan->returningLists) { List *newRL = NIL; ListCell *lcrl, *lcrr, *lcp; /* * Pass each per-subplan returningList through * set_returning_clause_references(). */ Assert(list_length(splan->returningLists) == list_length(splan->resultRelations)); Assert(list_length(splan->returningLists) == list_length(splan->plans)); forthree(lcrl, splan->returningLists, lcrr, splan->resultRelations, lcp, splan->plans) { List *rlist = (List *) lfirst(lcrl); Index resultrel = lfirst_int(lcrr); Plan *subplan = (Plan *) lfirst(lcp); rlist = set_returning_clause_references(root, rlist, subplan, resultrel, rtoffset); newRL = lappend(newRL, rlist); } splan->returningLists = newRL; /* * Set up the visible plan targetlist as being the same as * the first RETURNING list. This is for the use of * EXPLAIN; the executor won't pay any attention to the * targetlist. We postpone this step until here so that * we don't have to do set_returning_clause_references() * twice on identical targetlists. */ splan->plan.targetlist = copyObject(linitial(newRL)); } splan->nominalRelation += rtoffset; foreach(l, splan->resultRelations) { lfirst_int(l) += rtoffset; } foreach(l, splan->rowMarks) { PlanRowMark *rc = (PlanRowMark *) lfirst(l); rc->rti += rtoffset; rc->prti += rtoffset; } foreach(l, splan->plans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } /* * Append this ModifyTable node's final result relation RT * index(es) to the global list for the plan, and set its * resultRelIndex to reflect their starting position in the * global list. */ splan->resultRelIndex = list_length(root->glob->resultRelations); root->glob->resultRelations = list_concat(root->glob->resultRelations, list_copy(splan->resultRelations)); } break; case T_Append: { Append *splan = (Append *) plan; /* * Append, like Sort et al, doesn't actually evaluate its * targetlist or check quals. */ set_dummy_tlist_references(plan, rtoffset); Assert(splan->plan.qual == NIL); foreach(l, splan->appendplans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } } break; case T_MergeAppend: { MergeAppend *splan = (MergeAppend *) plan; /* * MergeAppend, like Sort et al, doesn't actually evaluate its * targetlist or check quals. */ set_dummy_tlist_references(plan, rtoffset); Assert(splan->plan.qual == NIL); foreach(l, splan->mergeplans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } } break; case T_RecursiveUnion: /* This doesn't evaluate targetlist or check quals either */ set_dummy_tlist_references(plan, rtoffset); Assert(plan->qual == NIL); break; case T_BitmapAnd: { BitmapAnd *splan = (BitmapAnd *) plan; /* BitmapAnd works like Append, but has no tlist */ Assert(splan->plan.targetlist == NIL); Assert(splan->plan.qual == NIL); foreach(l, splan->bitmapplans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } } break; case T_BitmapOr: { BitmapOr *splan = (BitmapOr *) plan; /* BitmapOr works like Append, but has no tlist */ Assert(splan->plan.targetlist == NIL); Assert(splan->plan.qual == NIL); foreach(l, splan->bitmapplans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } } break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(plan)); break; } /* * Now recurse into child plans, if any * * NOTE: it is essential that we recurse into child plans AFTER we set * subplan references in this plan's tlist and quals. If we did the * reference-adjustments bottom-up, then we would fail to match this * plan's var nodes against the already-modified nodes of the children. */ plan->lefttree = set_plan_refs(root, plan->lefttree, rtoffset); plan->righttree = set_plan_refs(root, plan->righttree, rtoffset); return plan; } /* * set_indexonlyscan_references * Do set_plan_references processing on an IndexOnlyScan * * This is unlike the handling of a plain IndexScan because we have to * convert Vars referencing the heap into Vars referencing the index. * We can use the fix_upper_expr machinery for that, by working from a * targetlist describing the index columns. */ static Plan * set_indexonlyscan_references(PlannerInfo *root, IndexOnlyScan *plan, int rtoffset) { indexed_tlist *index_itlist; index_itlist = build_tlist_index(plan->indextlist); plan->scan.scanrelid += rtoffset; plan->scan.plan.targetlist = (List *) fix_upper_expr(root, (Node *) plan->scan.plan.targetlist, index_itlist, INDEX_VAR, rtoffset); plan->scan.plan.qual = (List *) fix_upper_expr(root, (Node *) plan->scan.plan.qual, index_itlist, INDEX_VAR, rtoffset); /* indexqual is already transformed to reference index columns */ plan->indexqual = fix_scan_list(root, plan->indexqual, rtoffset); /* indexorderby is already transformed to reference index columns */ plan->indexorderby = fix_scan_list(root, plan->indexorderby, rtoffset); /* indextlist must NOT be transformed to reference index columns */ plan->indextlist = fix_scan_list(root, plan->indextlist, rtoffset); pfree(index_itlist); return (Plan *) plan; } /* * set_subqueryscan_references * Do set_plan_references processing on a SubqueryScan * * We try to strip out the SubqueryScan entirely; if we can't, we have * to do the normal processing on it. */ static Plan * set_subqueryscan_references(PlannerInfo *root, SubqueryScan *plan, int rtoffset) { RelOptInfo *rel; Plan *result; /* Need to look up the subquery's RelOptInfo, since we need its subroot */ rel = find_base_rel(root, plan->scan.scanrelid); Assert(rel->subplan == plan->subplan); /* Recursively process the subplan */ plan->subplan = set_plan_references(rel->subroot, plan->subplan); if (trivial_subqueryscan(plan)) { /* * We can omit the SubqueryScan node and just pull up the subplan. */ ListCell *lp, *lc; result = plan->subplan; /* We have to be sure we don't lose any initplans */ result->initPlan = list_concat(plan->scan.plan.initPlan, result->initPlan); /* * We also have to transfer the SubqueryScan's result-column names * into the subplan, else columns sent to client will be improperly * labeled if this is the topmost plan level. Copy the "source * column" information too. */ forboth(lp, plan->scan.plan.targetlist, lc, result->targetlist) { TargetEntry *ptle = (TargetEntry *) lfirst(lp); TargetEntry *ctle = (TargetEntry *) lfirst(lc); ctle->resname = ptle->resname; ctle->resorigtbl = ptle->resorigtbl; ctle->resorigcol = ptle->resorigcol; } } else { /* * Keep the SubqueryScan node. We have to do the processing that * set_plan_references would otherwise have done on it. Notice we do * not do set_upper_references() here, because a SubqueryScan will * always have been created with correct references to its subplan's * outputs to begin with. */ plan->scan.scanrelid += rtoffset; plan->scan.plan.targetlist = fix_scan_list(root, plan->scan.plan.targetlist, rtoffset); plan->scan.plan.qual = fix_scan_list(root, plan->scan.plan.qual, rtoffset); result = (Plan *) plan; } return result; } /* * trivial_subqueryscan * Detect whether a SubqueryScan can be deleted from the plan tree. * * We can delete it if it has no qual to check and the targetlist just * regurgitates the output of the child plan. */ static bool trivial_subqueryscan(SubqueryScan *plan) { int attrno; ListCell *lp, *lc; if (plan->scan.plan.qual != NIL) return false; if (list_length(plan->scan.plan.targetlist) != list_length(plan->subplan->targetlist)) return false; /* tlists not same length */ attrno = 1; forboth(lp, plan->scan.plan.targetlist, lc, plan->subplan->targetlist) { TargetEntry *ptle = (TargetEntry *) lfirst(lp); TargetEntry *ctle = (TargetEntry *) lfirst(lc); if (ptle->resjunk != ctle->resjunk) return false; /* tlist doesn't match junk status */ /* * We accept either a Var referencing the corresponding element of the * subplan tlist, or a Const equaling the subplan element. See * generate_setop_tlist() for motivation. */ if (ptle->expr && IsA(ptle->expr, Var)) { Var *var = (Var *) ptle->expr; Assert(var->varno == plan->scan.scanrelid); Assert(var->varlevelsup == 0); if (var->varattno != attrno) return false; /* out of order */ } else if (ptle->expr && IsA(ptle->expr, Const)) { if (!equal(ptle->expr, ctle->expr)) return false; } else return false; attrno++; } return true; } /* * copyVar * Copy a Var node. * * fix_scan_expr and friends do this enough times that it's worth having * a bespoke routine instead of using the generic copyObject() function. */ static inline Var * copyVar(Var *var) { Var *newvar = (Var *) palloc(sizeof(Var)); *newvar = *var; return newvar; } /* * fix_expr_common * Do generic set_plan_references processing on an expression node * * This is code that is common to all variants of expression-fixing. * We must look up operator opcode info for OpExpr and related nodes, * add OIDs from regclass Const nodes into root->glob->relationOids, and * add catalog TIDs for user-defined functions into root->glob->invalItems. * * We assume it's okay to update opcode info in-place. So this could possibly * scribble on the planner's input data structures, but it's OK. */ static void fix_expr_common(PlannerInfo *root, Node *node) { /* We assume callers won't call us on a NULL pointer */ if (IsA(node, Aggref)) { record_plan_function_dependency(root, ((Aggref *) node)->aggfnoid); } else if (IsA(node, WindowFunc)) { record_plan_function_dependency(root, ((WindowFunc *) node)->winfnoid); } else if (IsA(node, FuncExpr)) { record_plan_function_dependency(root, ((FuncExpr *) node)->funcid); } else if (IsA(node, OpExpr)) { set_opfuncid((OpExpr *) node); record_plan_function_dependency(root, ((OpExpr *) node)->opfuncid); } else if (IsA(node, DistinctExpr)) { set_opfuncid((OpExpr *) node); /* rely on struct equivalence */ record_plan_function_dependency(root, ((DistinctExpr *) node)->opfuncid); } else if (IsA(node, NullIfExpr)) { set_opfuncid((OpExpr *) node); /* rely on struct equivalence */ record_plan_function_dependency(root, ((NullIfExpr *) node)->opfuncid); } else if (IsA(node, ScalarArrayOpExpr)) { set_sa_opfuncid((ScalarArrayOpExpr *) node); record_plan_function_dependency(root, ((ScalarArrayOpExpr *) node)->opfuncid); } else if (IsA(node, ArrayCoerceExpr)) { if (OidIsValid(((ArrayCoerceExpr *) node)->elemfuncid)) record_plan_function_dependency(root, ((ArrayCoerceExpr *) node)->elemfuncid); } else if (IsA(node, Const)) { Const *con = (Const *) node; /* Check for regclass reference */ if (ISREGCLASSCONST(con)) root->glob->relationOids = lappend_oid(root->glob->relationOids, DatumGetObjectId(con->constvalue)); } } /* * fix_param_node * Do set_plan_references processing on a Param * * If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from * root->multiexpr_params; otherwise no change is needed. * Just for paranoia's sake, we make a copy of the node in either case. */ static Node * fix_param_node(PlannerInfo *root, Param *p) { if (p->paramkind == PARAM_MULTIEXPR) { int subqueryid = p->paramid >> 16; int colno = p->paramid & 0xFFFF; List *params; if (subqueryid <= 0 || subqueryid > list_length(root->multiexpr_params)) elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid); params = (List *) list_nth(root->multiexpr_params, subqueryid - 1); if (colno <= 0 || colno > list_length(params)) elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid); return copyObject(list_nth(params, colno - 1)); } return copyObject(p); } /* * fix_scan_expr * Do set_plan_references processing on a scan-level expression * * This consists of incrementing all Vars' varnos by rtoffset, * replacing PARAM_MULTIEXPR Params, expanding PlaceHolderVars, * looking up operator opcode info for OpExpr and related nodes, * and adding OIDs from regclass Const nodes into root->glob->relationOids. */ static Node * fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset) { fix_scan_expr_context context; context.root = root; context.rtoffset = rtoffset; if (rtoffset != 0 || root->multiexpr_params != NIL || root->glob->lastPHId != 0) { return fix_scan_expr_mutator(node, &context); } else { /* * If rtoffset == 0, we don't need to change any Vars, and if there * are no MULTIEXPR subqueries then we don't need to replace * PARAM_MULTIEXPR Params, and if there are no placeholders anywhere * we won't need to remove them. Then it's OK to just scribble on the * input node tree instead of copying (since the only change, filling * in any unset opfuncid fields, is harmless). This saves just enough * cycles to be noticeable on trivial queries. */ (void) fix_scan_expr_walker(node, &context); return node; } } static Node * fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context) { if (node == NULL) return NULL; if (IsA(node, Var)) { Var *var = copyVar((Var *) node); Assert(var->varlevelsup == 0); /* * We should not see any Vars marked INNER_VAR or OUTER_VAR. But an * indexqual expression could contain INDEX_VAR Vars. */ Assert(var->varno != INNER_VAR); Assert(var->varno != OUTER_VAR); if (!IS_SPECIAL_VARNO(var->varno)) var->varno += context->rtoffset; if (var->varnoold > 0) var->varnoold += context->rtoffset; return (Node *) var; } if (IsA(node, Param)) return fix_param_node(context->root, (Param *) node); if (IsA(node, CurrentOfExpr)) { CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node); Assert(cexpr->cvarno != INNER_VAR); Assert(cexpr->cvarno != OUTER_VAR); if (!IS_SPECIAL_VARNO(cexpr->cvarno)) cexpr->cvarno += context->rtoffset; return (Node *) cexpr; } if (IsA(node, PlaceHolderVar)) { /* At scan level, we should always just evaluate the contained expr */ PlaceHolderVar *phv = (PlaceHolderVar *) node; return fix_scan_expr_mutator((Node *) phv->phexpr, context); } fix_expr_common(context->root, node); return expression_tree_mutator(node, fix_scan_expr_mutator, (void *) context); } static bool fix_scan_expr_walker(Node *node, fix_scan_expr_context *context) { if (node == NULL) return false; Assert(!IsA(node, PlaceHolderVar)); fix_expr_common(context->root, node); return expression_tree_walker(node, fix_scan_expr_walker, (void *) context); } /* * set_join_references * Modify the target list and quals of a join node to reference its * subplans, by setting the varnos to OUTER_VAR or INNER_VAR and setting * attno values to the result domain number of either the corresponding * outer or inner join tuple item. Also perform opcode lookup for these * expressions. and add regclass OIDs to root->glob->relationOids. */ static void set_join_references(PlannerInfo *root, Join *join, int rtoffset) { 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 = fix_join_expr(root, join->plan.targetlist, outer_itlist, inner_itlist, (Index) 0, rtoffset); join->plan.qual = fix_join_expr(root, join->plan.qual, outer_itlist, inner_itlist, (Index) 0, rtoffset); join->joinqual = fix_join_expr(root, join->joinqual, outer_itlist, inner_itlist, (Index) 0, rtoffset); /* Now do join-type-specific stuff */ if (IsA(join, NestLoop)) { NestLoop *nl = (NestLoop *) join; ListCell *lc; foreach(lc, nl->nestParams) { NestLoopParam *nlp = (NestLoopParam *) lfirst(lc); nlp->paramval = (Var *) fix_upper_expr(root, (Node *) nlp->paramval, outer_itlist, OUTER_VAR, rtoffset); /* Check we replaced any PlaceHolderVar with simple Var */ if (!(IsA(nlp->paramval, Var) && nlp->paramval->varno == OUTER_VAR)) elog(ERROR, "NestLoopParam was not reduced to a simple Var"); } } else if (IsA(join, MergeJoin)) { MergeJoin *mj = (MergeJoin *) join; mj->mergeclauses = fix_join_expr(root, mj->mergeclauses, outer_itlist, inner_itlist, (Index) 0, rtoffset); } else if (IsA(join, HashJoin)) { HashJoin *hj = (HashJoin *) join; hj->hashclauses = fix_join_expr(root, hj->hashclauses, outer_itlist, inner_itlist, (Index) 0, rtoffset); } pfree(outer_itlist); pfree(inner_itlist); } /* * set_upper_references * Update the targetlist and quals of an upper-level plan node * to refer to the tuples returned by its lefttree subplan. * Also perform opcode lookup for these expressions, and * add regclass OIDs to root->glob->relationOids. * * 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_upper_references(PlannerInfo *root, Plan *plan, int rtoffset) { Plan *subplan = plan->lefttree; indexed_tlist *subplan_itlist; List *output_targetlist; ListCell *l; subplan_itlist = build_tlist_index(subplan->targetlist); output_targetlist = NIL; foreach(l, plan->targetlist) { TargetEntry *tle = (TargetEntry *) lfirst(l); Node *newexpr; /* If it's a non-Var sort/group item, first try to match by sortref */ if (tle->ressortgroupref != 0 && !IsA(tle->expr, Var)) { newexpr = (Node *) search_indexed_tlist_for_sortgroupref((Node *) tle->expr, tle->ressortgroupref, subplan_itlist, OUTER_VAR); if (!newexpr) newexpr = fix_upper_expr(root, (Node *) tle->expr, subplan_itlist, OUTER_VAR, rtoffset); } else newexpr = fix_upper_expr(root, (Node *) tle->expr, subplan_itlist, OUTER_VAR, rtoffset); tle = flatCopyTargetEntry(tle); tle->expr = (Expr *) newexpr; output_targetlist = lappend(output_targetlist, tle); } plan->targetlist = output_targetlist; plan->qual = (List *) fix_upper_expr(root, (Node *) plan->qual, subplan_itlist, OUTER_VAR, rtoffset); pfree(subplan_itlist); } /* * set_dummy_tlist_references * Replace the targetlist of an upper-level plan node with a simple * list of OUTER_VAR references to its child. * * This is used for plan types like Sort and Append that don't evaluate * their targetlists. Although the executor doesn't care at all what's in * the tlist, EXPLAIN needs it to be realistic. * * Note: we could almost use set_upper_references() here, but it fails for * Append for lack of a lefttree subplan. Single-purpose code is faster * anyway. */ static void set_dummy_tlist_references(Plan *plan, int rtoffset) { List *output_targetlist; ListCell *l; output_targetlist = NIL; foreach(l, plan->targetlist) { TargetEntry *tle = (TargetEntry *) lfirst(l); Var *oldvar = (Var *) tle->expr; Var *newvar; newvar = makeVar(OUTER_VAR, tle->resno, exprType((Node *) oldvar), exprTypmod((Node *) oldvar), exprCollation((Node *) oldvar), 0); if (IsA(oldvar, Var)) { newvar->varnoold = oldvar->varno + rtoffset; newvar->varoattno = oldvar->varattno; } else { newvar->varnoold = 0; /* wasn't ever a plain Var */ newvar->varoattno = 0; } tle = flatCopyTargetEntry(tle); tle->expr = (Expr *) newvar; output_targetlist = lappend(output_targetlist, tle); } plan->targetlist = output_targetlist; /* We don't touch plan->qual here */ } /* * 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_ph_vars = false; 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 if (tle->expr && IsA(tle->expr, PlaceHolderVar)) itlist->has_ph_vars = true; 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 belonging to some rel other than the one specified. We will set * has_ph_vars (allowing PlaceHolderVars to be matched), but not has_non_vars * (so nothing other than Vars and PlaceHolderVars can be matched). */ 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_ph_vars = false; 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++; } } else if (tle->expr && IsA(tle->expr, PlaceHolderVar)) itlist->has_ph_vars = true; } 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). * Also ensure that varnoold is incremented by rtoffset. * If no match, return NULL. */ static Var * search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist, Index newvarno, int rtoffset) { 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 = copyVar(var); newvar->varno = newvarno; newvar->varattno = vinfo->resno; if (newvar->varnoold > 0) newvar->varnoold += rtoffset; 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 unless itlist->has_ph_vars or * 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 = makeVarFromTargetEntry(newvarno, tle); newvar->varnoold = 0; /* wasn't ever a plain Var */ newvar->varoattno = 0; return newvar; } return NULL; /* no match */ } /* * search_indexed_tlist_for_sortgroupref --- find a sort/group expression * (which is assumed not to be just a Var) * * If a match is found, return a Var constructed to reference the tlist item. * If no match, return NULL. * * This is needed to ensure that we select the right subplan TLE in cases * where there are multiple textually-equal()-but-volatile sort expressions. * And it's also faster than search_indexed_tlist_for_non_var. */ static Var * search_indexed_tlist_for_sortgroupref(Node *node, Index sortgroupref, indexed_tlist *itlist, Index newvarno) { ListCell *lc; foreach(lc, itlist->tlist) { TargetEntry *tle = (TargetEntry *) lfirst(lc); /* The equal() check should be redundant, but let's be paranoid */ if (tle->ressortgroupref == sortgroupref && equal(node, tle->expr)) { /* Found a matching subplan output expression */ Var *newvar; newvar = makeVarFromTargetEntry(newvarno, tle); newvar->varnoold = 0; /* wasn't ever a plain Var */ newvar->varoattno = 0; return newvar; } } return NULL; /* no match */ } /* * fix_join_expr * Create 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. Also perform opcode lookup and add * regclass OIDs to root->glob->relationOids. * * This is used in two different scenarios: a normal join clause, where all * the Vars in the clause *must* be replaced by OUTER_VAR or INNER_VAR * references; and a RETURNING clause, which may contain both Vars of the * target relation and Vars of other relations. In the latter case we want * to replace the other-relation Vars by OUTER_VAR references, while leaving * target Vars alone. * * 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 RETURNING case, pass * inner_itlist = NULL and acceptable_rel = the ID of the target 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 * 'rtoffset': how much to increment varnoold by * * Returns the new expression tree. The original clause structure is * not modified. */ static List * fix_join_expr(PlannerInfo *root, List *clauses, indexed_tlist *outer_itlist, indexed_tlist *inner_itlist, Index acceptable_rel, int rtoffset) { fix_join_expr_context context; context.root = root; context.outer_itlist = outer_itlist; context.inner_itlist = inner_itlist; context.acceptable_rel = acceptable_rel; context.rtoffset = rtoffset; return (List *) fix_join_expr_mutator((Node *) clauses, &context); } static Node * fix_join_expr_mutator(Node *node, fix_join_expr_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_VAR, context->rtoffset); if (newvar) return (Node *) newvar; if (context->inner_itlist) { newvar = search_indexed_tlist_for_var(var, context->inner_itlist, INNER_VAR, context->rtoffset); if (newvar) return (Node *) newvar; } /* If it's for acceptable_rel, adjust and return it */ if (var->varno == context->acceptable_rel) { var = copyVar(var); var->varno += context->rtoffset; if (var->varnoold > 0) var->varnoold += context->rtoffset; return (Node *) var; } /* No referent found for Var */ elog(ERROR, "variable not found in subplan target lists"); } if (IsA(node, PlaceHolderVar)) { PlaceHolderVar *phv = (PlaceHolderVar *) node; /* See if the PlaceHolderVar has bubbled up from a lower plan node */ if (context->outer_itlist->has_ph_vars) { newvar = search_indexed_tlist_for_non_var((Node *) phv, context->outer_itlist, OUTER_VAR); if (newvar) return (Node *) newvar; } if (context->inner_itlist && context->inner_itlist->has_ph_vars) { newvar = search_indexed_tlist_for_non_var((Node *) phv, context->inner_itlist, INNER_VAR); if (newvar) return (Node *) newvar; } /* If not supplied by input plans, evaluate the contained expr */ return fix_join_expr_mutator((Node *) phv->phexpr, context); } if (IsA(node, Param)) return fix_param_node(context->root, (Param *) node); /* 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_VAR); 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_VAR); if (newvar) return (Node *) newvar; } fix_expr_common(context->root, node); return expression_tree_mutator(node, fix_join_expr_mutator, (void *) context); } /* * fix_upper_expr * Modifies an expression tree so that all Var nodes reference outputs * of a subplan. Also performs opcode lookup, and adds regclass OIDs to * root->glob->relationOids. * * This is used to fix up target and qual expressions of non-join upper-level * plan nodes, as well as index-only scan 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 (or index) * 'newvarno': varno to use for Vars referencing tlist elements * 'rtoffset': how much to increment varnoold by * * The resulting tree is a copy of the original in which all Var nodes have * varno = newvarno, varattno = resno of corresponding targetlist element. * The original tree is not modified. */ static Node * fix_upper_expr(PlannerInfo *root, Node *node, indexed_tlist *subplan_itlist, Index newvarno, int rtoffset) { fix_upper_expr_context context; context.root = root; context.subplan_itlist = subplan_itlist; context.newvarno = newvarno; context.rtoffset = rtoffset; return fix_upper_expr_mutator(node, &context); } static Node * fix_upper_expr_mutator(Node *node, fix_upper_expr_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->newvarno, context->rtoffset); if (!newvar) elog(ERROR, "variable not found in subplan target list"); return (Node *) newvar; } if (IsA(node, PlaceHolderVar)) { PlaceHolderVar *phv = (PlaceHolderVar *) node; /* See if the PlaceHolderVar has bubbled up from a lower plan node */ if (context->subplan_itlist->has_ph_vars) { newvar = search_indexed_tlist_for_non_var((Node *) phv, context->subplan_itlist, context->newvarno); if (newvar) return (Node *) newvar; } /* If not supplied by input plan, evaluate the contained expr */ return fix_upper_expr_mutator((Node *) phv->phexpr, context); } if (IsA(node, Param)) return fix_param_node(context->root, (Param *) node); /* 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->newvarno); if (newvar) return (Node *) newvar; } fix_expr_common(context->root, node); return expression_tree_mutator(node, fix_upper_expr_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 subplan'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 have their original * varno (plus rtoffset), but Vars for other rels will have varno OUTER_VAR. * * We also must perform opcode lookup and add regclass OIDs to * root->glob->relationOids. * * 'rlist': the RETURNING targetlist to be fixed * 'topplan': the top subplan node that will be just below the ModifyTable * node (note it's not yet passed through set_plan_refs) * 'resultRelation': RT index of the associated result relation * 'rtoffset': how much to increment varnos by * * Note: the given 'root' is for the parent query level, not the 'topplan'. * This does not matter currently since we only access the dependency-item * lists in root->glob, but it would need some hacking if we wanted a root * that actually matches the subplan. * * Note: resultRelation is not yet adjusted by rtoffset. */ static List * set_returning_clause_references(PlannerInfo *root, List *rlist, Plan *topplan, Index resultRelation, int rtoffset) { indexed_tlist *itlist; /* * We can perform the desired Var fixup by abusing the fix_join_expr * machinery that formerly handled inner indexscan fixup. We search the * top plan's targetlist for Vars of non-result relations, and use * fix_join_expr to convert RETURNING Vars into references to those tlist * entries, while leaving result-rel Vars as-is. * * PlaceHolderVars will also be sought in the targetlist, but no * more-complex expressions will be. Note that it is not possible for a * PlaceHolderVar to refer to the result relation, since the result is * never below an outer join. If that case could happen, we'd have to be * prepared to pick apart the PlaceHolderVar and evaluate its contained * expression instead. */ itlist = build_tlist_index_other_vars(topplan->targetlist, resultRelation); rlist = fix_join_expr(root, rlist, itlist, NULL, resultRelation, rtoffset); 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, NullIfExpr)) set_opfuncid((OpExpr *) node); /* rely on struct equivalence */ else if (IsA(node, ScalarArrayOpExpr)) set_sa_opfuncid((ScalarArrayOpExpr *) node); 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); } /***************************************************************************** * QUERY DEPENDENCY MANAGEMENT *****************************************************************************/ /* * record_plan_function_dependency * Mark the current plan as depending on a particular function. * * This is exported so that the function-inlining code can record a * dependency on a function that it's removed from the plan tree. */ void record_plan_function_dependency(PlannerInfo *root, Oid funcid) { /* * For performance reasons, we don't bother to track built-in functions; * we just assume they'll never change (or at least not in ways that'd * invalidate plans using them). For this purpose we can consider a * built-in function to be one with OID less than FirstBootstrapObjectId. * Note that the OID generator guarantees never to generate such an OID * after startup, even at OID wraparound. */ if (funcid >= (Oid) FirstBootstrapObjectId) { PlanInvalItem *inval_item = makeNode(PlanInvalItem); /* * It would work to use any syscache on pg_proc, but the easiest is * PROCOID since we already have the function's OID at hand. Note * that plancache.c knows we use PROCOID. */ inval_item->cacheId = PROCOID; inval_item->hashValue = GetSysCacheHashValue1(PROCOID, ObjectIdGetDatum(funcid)); root->glob->invalItems = lappend(root->glob->invalItems, inval_item); } } /* * extract_query_dependencies * Given a not-yet-planned query or queries (i.e. a Query node or list * of Query nodes), extract dependencies just as set_plan_references * would do. * * This is needed by plancache.c to handle invalidation of cached unplanned * queries. */ void extract_query_dependencies(Node *query, List **relationOids, List **invalItems, bool *hasRowSecurity) { PlannerGlobal glob; PlannerInfo root; /* Make up dummy planner state so we can use this module's machinery */ MemSet(&glob, 0, sizeof(glob)); glob.type = T_PlannerGlobal; glob.relationOids = NIL; glob.invalItems = NIL; glob.hasRowSecurity = false; MemSet(&root, 0, sizeof(root)); root.type = T_PlannerInfo; root.glob = &glob; (void) extract_query_dependencies_walker(query, &root); *relationOids = glob.relationOids; *invalItems = glob.invalItems; *hasRowSecurity = glob.hasRowSecurity; } static bool extract_query_dependencies_walker(Node *node, PlannerInfo *context) { if (node == NULL) return false; Assert(!IsA(node, PlaceHolderVar)); /* Extract function dependencies and check for regclass Consts */ fix_expr_common(context, node); if (IsA(node, Query)) { Query *query = (Query *) node; ListCell *lc; /* Collect row security information */ context->glob->hasRowSecurity = query->hasRowSecurity; if (query->commandType == CMD_UTILITY) { /* * Ignore utility statements, except those (such as EXPLAIN) that * contain a parsed-but-not-planned query. */ query = UtilityContainsQuery(query->utilityStmt); if (query == NULL) return false; } /* Collect relation OIDs in this Query's rtable */ foreach(lc, query->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); if (rte->rtekind == RTE_RELATION) context->glob->relationOids = lappend_oid(context->glob->relationOids, rte->relid); } /* And recurse into the query's subexpressions */ return query_tree_walker(query, extract_query_dependencies_walker, (void *) context, 0); } return expression_tree_walker(node, extract_query_dependencies_walker, (void *) context); }