/*------------------------------------------------------------------------- * * setrefs.c * Post-processing of a completed plan tree: fix references to subplan * vars, compute regproc values for operators, etc * * Portions Copyright (c) 1996-2025, 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/optimizer.h" #include "optimizer/pathnode.h" #include "optimizer/planmain.h" #include "optimizer/planner.h" #include "optimizer/subselect.h" #include "optimizer/tlist.h" #include "parser/parse_relation.h" #include "rewrite/rewriteManip.h" #include "tcop/utility.h" #include "utils/syscache.h" typedef enum { NRM_EQUAL, /* expect exact match of nullingrels */ NRM_SUBSET, /* actual Var may have a subset of input */ NRM_SUPERSET, /* actual Var may have a superset of input */ } NullingRelsMatch; typedef struct { int varno; /* RT index of Var */ AttrNumber varattno; /* attr number of Var */ AttrNumber resno; /* TLE position of Var */ Bitmapset *varnullingrels; /* Var's varnullingrels */ } 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; double num_exec; } fix_scan_expr_context; typedef struct { PlannerInfo *root; indexed_tlist *outer_itlist; indexed_tlist *inner_itlist; Index acceptable_rel; int rtoffset; NullingRelsMatch nrm_match; double num_exec; } fix_join_expr_context; typedef struct { PlannerInfo *root; indexed_tlist *subplan_itlist; int newvarno; int rtoffset; NullingRelsMatch nrm_match; double num_exec; } fix_upper_expr_context; typedef struct { PlannerInfo *root; indexed_tlist *subplan_itlist; int newvarno; } fix_windowagg_cond_context; /* Context info for flatten_rtes_walker() */ typedef struct { PlannerGlobal *glob; Query *query; } flatten_rtes_walker_context; /* * Selecting the best alternative in an AlternativeSubPlan expression requires * estimating how many times that expression will be evaluated. For an * expression in a plan node's targetlist, the plan's estimated number of * output rows is clearly what to use, but for an expression in a qual it's * far less clear. Since AlternativeSubPlans aren't heavily used, we don't * want to expend a lot of cycles making such estimates. What we use is twice * the number of output rows. That's not entirely unfounded: we know that * clause_selectivity() would fall back to a default selectivity estimate * of 0.5 for any SubPlan, so if the qual containing the SubPlan is the last * to be applied (which it likely would be, thanks to order_qual_clauses()), * this matches what we could have estimated in a far more laborious fashion. * Obviously there are many other scenarios, but it's probably not worth the * trouble to try to improve on this estimate, especially not when we don't * have a better estimate for the selectivity of the SubPlan qual itself. */ #define NUM_EXEC_TLIST(parentplan) ((parentplan)->plan_rows) #define NUM_EXEC_QUAL(parentplan) ((parentplan)->plan_rows * 2.0) /* * 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, num_exec) \ ((List *) fix_scan_expr(root, (Node *) (lst), rtoffset, num_exec)) 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, flatten_rtes_walker_context *cxt); static void add_rte_to_flat_rtable(PlannerGlobal *glob, List *rteperminfos, 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 Plan *clean_up_removed_plan_level(Plan *parent, Plan *child); static void set_foreignscan_references(PlannerInfo *root, ForeignScan *fscan, int rtoffset); static void set_customscan_references(PlannerInfo *root, CustomScan *cscan, int rtoffset); static Plan *set_append_references(PlannerInfo *root, Append *aplan, int rtoffset); static Plan *set_mergeappend_references(PlannerInfo *root, MergeAppend *mplan, int rtoffset); static void set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset); static Relids offset_relid_set(Relids relids, int rtoffset); static Node *fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec); 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_param_references(PlannerInfo *root, Plan *plan); static Node *convert_combining_aggrefs(Node *node, void *context); 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, int newvarno, int rtoffset, NullingRelsMatch nrm_match); static Var *search_indexed_tlist_for_phv(PlaceHolderVar *phv, indexed_tlist *itlist, int newvarno, NullingRelsMatch nrm_match); static Var *search_indexed_tlist_for_non_var(Expr *node, indexed_tlist *itlist, int newvarno); static Var *search_indexed_tlist_for_sortgroupref(Expr *node, Index sortgroupref, indexed_tlist *itlist, int newvarno); static List *fix_join_expr(PlannerInfo *root, List *clauses, indexed_tlist *outer_itlist, indexed_tlist *inner_itlist, Index acceptable_rel, int rtoffset, NullingRelsMatch nrm_match, double num_exec); 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, int newvarno, int rtoffset, NullingRelsMatch nrm_match, double num_exec); 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 List *set_windowagg_runcondition_references(PlannerInfo *root, List *runcondition, Plan *plan); /***************************************************************************** * * 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. Aggrefs in Agg plan nodes need to be adjusted in some cases involving * partial aggregation or minmax aggregate optimization. * * 5. PARAM_MULTIEXPR Params are replaced by regular PARAM_EXEC Params, * now that we have finished planning all MULTIEXPR subplans. * * 6. AlternativeSubPlan expressions are replaced by just one of their * alternatives, using an estimate of how many times they'll be executed. * * 7. We compute regproc OIDs for operators (ie, we look up the function * that implements each op). * * 8. 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, user-defined functions, and domains are the only * types of objects that are explicitly tracked this way. * * 9. We assign every plan node in the tree a unique ID. * * We also perform one final optimization step, which is to delete * SubqueryScan, Append, and MergeAppend plan nodes that aren't doing * anything useful. 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 child plan's top tlist * wouldn't match up with the Vars in the outer plan tree. A 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. * Likewise, Append and MergeAppend buffer between the parent and child vars * of an appendrel, but we don't need to worry about that once we've done * set_plan_references. * * 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 node 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, * and flattened AppendRelInfos are appended to root->glob->appendRelations. * 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) { Plan *result; 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 = lfirst_node(PlanRowMark, lc); PlanRowMark *newrc; /* sanity check on existing row marks */ Assert(root->simple_rel_array[rc->rti] != NULL && root->simple_rte_array[rc->rti] != NULL); /* 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); } /* * Adjust RT indexes of AppendRelInfos and add to final appendrels list. * We assume the AppendRelInfos were built during planning and don't need * to be copied. */ foreach(lc, root->append_rel_list) { AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc); /* adjust RT indexes */ appinfo->parent_relid += rtoffset; appinfo->child_relid += rtoffset; /* * Rather than adjust the translated_vars entries, just drop 'em. * Neither the executor nor EXPLAIN currently need that data. */ appinfo->translated_vars = NIL; glob->appendRelations = lappend(glob->appendRelations, appinfo); } /* If needed, create workspace for processing AlternativeSubPlans */ if (root->hasAlternativeSubPlans) { root->isAltSubplan = (bool *) palloc0(list_length(glob->subplans) * sizeof(bool)); root->isUsedSubplan = (bool *) palloc0(list_length(glob->subplans) * sizeof(bool)); } /* Now fix the Plan tree */ result = set_plan_refs(root, plan, rtoffset); /* * If we have AlternativeSubPlans, it is likely that we now have some * unreferenced subplans in glob->subplans. To avoid expending cycles on * those subplans later, get rid of them by setting those list entries to * NULL. (Note: we can't do this immediately upon processing an * AlternativeSubPlan, because there may be multiple copies of the * AlternativeSubPlan, and they can get resolved differently.) */ if (root->hasAlternativeSubPlans) { foreach(lc, glob->subplans) { int ndx = foreach_current_index(lc); /* * If it was used by some AlternativeSubPlan in this query level, * but wasn't selected as best by any AlternativeSubPlan, then we * don't need it. Do not touch subplans that aren't parts of * AlternativeSubPlans. */ if (root->isAltSubplan[ndx] && !root->isUsedSubplan[ndx]) lfirst(lc) = NULL; } } return result; } /* * Extract RangeTblEntries from the plan's rangetable, and add to flat rtable * * This can recurse into subquery plans; "recursing" is true if so. * * This also seems like a good place to add the query's RTEPermissionInfos to * the flat rteperminfos. */ 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 (and subquery * RTEs that were once relation RTEs). */ foreach(lc, root->parse->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); if (!recursing || rte->rtekind == RTE_RELATION || (rte->rtekind == RTE_SUBQUERY && OidIsValid(rte->relid))) add_rte_to_flat_rtable(glob, root->parse->rteperminfos, 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 result rel 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 subquery 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->subroot == NULL) flatten_unplanned_rtes(glob, rte); else if (recursing || IS_DUMMY_REL(fetch_upper_rel(rel->subroot, UPPERREL_FINAL, 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) { flatten_rtes_walker_context cxt = {glob, rte->subquery}; /* Use query_tree_walker to find all RTEs in the parse tree */ (void) query_tree_walker(rte->subquery, flatten_rtes_walker, &cxt, QTW_EXAMINE_RTES_BEFORE); } static bool flatten_rtes_walker(Node *node, flatten_rtes_walker_context *cxt) { if (node == NULL) return false; if (IsA(node, RangeTblEntry)) { RangeTblEntry *rte = (RangeTblEntry *) node; /* As above, we need only save relation RTEs and former relations */ if (rte->rtekind == RTE_RELATION || (rte->rtekind == RTE_SUBQUERY && OidIsValid(rte->relid))) add_rte_to_flat_rtable(cxt->glob, cxt->query->rteperminfos, rte); return false; } if (IsA(node, Query)) { /* * Recurse into subselects. Must update cxt->query to this query so * that the rtable and rteperminfos correspond with each other. */ Query *save_query = cxt->query; bool result; cxt->query = (Query *) node; result = query_tree_walker((Query *) node, flatten_rtes_walker, cxt, QTW_EXAMINE_RTES_BEFORE); cxt->query = save_query; return result; } return expression_tree_walker(node, flatten_rtes_walker, cxt); } /* * Add (a copy of) the given RTE to the final rangetable and also the * corresponding RTEPermissionInfo, if any, to final rteperminfos. * * 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 ctename, alias, eref Alias fields, * which are needed by EXPLAIN, and perminfoindex which is needed by the * executor to fetch the RTE's RTEPermissionInfo. */ static void add_rte_to_flat_rtable(PlannerGlobal *glob, List *rteperminfos, 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->tablesample = NULL; newrte->subquery = NULL; newrte->joinaliasvars = NIL; newrte->joinleftcols = NIL; newrte->joinrightcols = NIL; newrte->join_using_alias = NULL; newrte->functions = NIL; newrte->tablefunc = NULL; newrte->values_lists = NIL; newrte->coltypes = NIL; newrte->coltypmods = NIL; newrte->colcollations = NIL; newrte->groupexprs = NIL; newrte->securityQuals = NIL; glob->finalrtable = lappend(glob->finalrtable, newrte); /* * If it's a plain relation RTE (or a subquery that was once a view * reference), add the relation OID to relationOids. Also add its new RT * index to the set of relations to be potentially accessed during * execution. * * 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 || (newrte->rtekind == RTE_SUBQUERY && OidIsValid(newrte->relid))) { glob->relationOids = lappend_oid(glob->relationOids, newrte->relid); glob->allRelids = bms_add_member(glob->allRelids, list_length(glob->finalrtable)); } /* * Add a copy of the RTEPermissionInfo, if any, corresponding to this RTE * to the flattened global list. */ if (rte->perminfoindex > 0) { RTEPermissionInfo *perminfo; RTEPermissionInfo *newperminfo; /* Get the existing one from this query's rteperminfos. */ perminfo = getRTEPermissionInfo(rteperminfos, newrte); /* * Add a new one to finalrteperminfos and copy the contents of the * existing one into it. Note that addRTEPermissionInfo() also * updates newrte->perminfoindex to point to newperminfo in * finalrteperminfos. */ newrte->perminfoindex = 0; /* expected by addRTEPermissionInfo() */ newperminfo = addRTEPermissionInfo(&glob->finalrteperminfos, newrte); memcpy(newperminfo, perminfo, sizeof(RTEPermissionInfo)); } } /* * 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; /* Assign this node a unique ID. */ plan->plan_node_id = root->glob->lastPlanNodeId++; /* * Plan-type-specific fixes */ switch (nodeTag(plan)) { case T_SeqScan: { SeqScan *splan = (SeqScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); } break; case T_SampleScan: { SampleScan *splan = (SampleScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->tablesample = (TableSampleClause *) fix_scan_expr(root, (Node *) splan->tablesample, rtoffset, 1); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->indexqual = fix_scan_list(root, splan->indexqual, rtoffset, 1); splan->indexqualorig = fix_scan_list(root, splan->indexqualorig, rtoffset, NUM_EXEC_QUAL(plan)); splan->indexorderby = fix_scan_list(root, splan->indexorderby, rtoffset, 1); splan->indexorderbyorig = fix_scan_list(root, splan->indexorderbyorig, rtoffset, NUM_EXEC_QUAL(plan)); } 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, 1); splan->indexqualorig = fix_scan_list(root, splan->indexqualorig, rtoffset, NUM_EXEC_QUAL(plan)); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->bitmapqualorig = fix_scan_list(root, splan->bitmapqualorig, rtoffset, NUM_EXEC_QUAL(plan)); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->tidquals = fix_scan_list(root, splan->tidquals, rtoffset, 1); } break; case T_TidRangeScan: { TidRangeScan *splan = (TidRangeScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->tidrangequals = fix_scan_list(root, splan->tidrangequals, rtoffset, 1); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->functions = fix_scan_list(root, splan->functions, rtoffset, 1); } break; case T_TableFuncScan: { TableFuncScan *splan = (TableFuncScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->tablefunc = (TableFunc *) fix_scan_expr(root, (Node *) splan->tablefunc, rtoffset, 1); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); splan->values_lists = fix_scan_list(root, splan->values_lists, rtoffset, 1); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); } break; case T_NamedTuplestoreScan: { NamedTuplestoreScan *splan = (NamedTuplestoreScan *) plan; splan->scan.scanrelid += rtoffset; splan->scan.plan.targetlist = fix_scan_list(root, splan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); } 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, NUM_EXEC_TLIST(plan)); splan->scan.plan.qual = fix_scan_list(root, splan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); } break; case T_ForeignScan: set_foreignscan_references(root, (ForeignScan *) plan, rtoffset); break; case T_CustomScan: set_customscan_references(root, (CustomScan *) plan, rtoffset); break; case T_NestLoop: case T_MergeJoin: case T_HashJoin: set_join_references(root, (Join *) plan, rtoffset); break; case T_Gather: case T_GatherMerge: { set_upper_references(root, plan, rtoffset); set_param_references(root, plan); } break; case T_Hash: set_hash_references(root, plan, rtoffset); break; case T_Memoize: { Memoize *mplan = (Memoize *) plan; /* * Memoize does not evaluate its targetlist. It just uses the * same targetlist from its outer subnode. */ set_dummy_tlist_references(plan, rtoffset); mplan->param_exprs = fix_scan_list(root, mplan->param_exprs, rtoffset, NUM_EXEC_TLIST(plan)); break; } case T_Material: case T_Sort: case T_IncrementalSort: 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, 1); splan->limitCount = fix_scan_expr(root, splan->limitCount, rtoffset, 1); } break; case T_Agg: { Agg *agg = (Agg *) plan; /* * If this node is combining partial-aggregation results, we * must convert its Aggrefs to contain references to the * partial-aggregate subexpressions that will be available * from the child plan node. */ if (DO_AGGSPLIT_COMBINE(agg->aggsplit)) { plan->targetlist = (List *) convert_combining_aggrefs((Node *) plan->targetlist, NULL); plan->qual = (List *) convert_combining_aggrefs((Node *) plan->qual, NULL); } set_upper_references(root, plan, rtoffset); } break; case T_Group: set_upper_references(root, plan, rtoffset); break; case T_WindowAgg: { WindowAgg *wplan = (WindowAgg *) plan; /* * Adjust the WindowAgg's run conditions by swapping the * WindowFuncs references out to instead reference the Var in * the scan slot so that when the executor evaluates the * runCondition, it receives the WindowFunc's value from the * slot that the result has just been stored into rather than * evaluating the WindowFunc all over again. */ wplan->runCondition = set_windowagg_runcondition_references(root, wplan->runCondition, (Plan *) wplan); 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, 1); wplan->endOffset = fix_scan_expr(root, wplan->endOffset, rtoffset, 1); wplan->runCondition = fix_scan_list(root, wplan->runCondition, rtoffset, NUM_EXEC_TLIST(plan)); wplan->runConditionOrig = fix_scan_list(root, wplan->runConditionOrig, rtoffset, NUM_EXEC_TLIST(plan)); } 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 { /* * The tlist of a childless Result could contain * unresolved ROWID_VAR Vars, in case it's representing a * target relation which is completely empty because of * constraint exclusion. Replace any such Vars by null * constants, as though they'd been resolved for a leaf * scan node that doesn't support them. We could have * fix_scan_expr do this, but since the case is only * expected to occur here, it seems safer to special-case * it here and keep the assertions that ROWID_VARs * shouldn't be seen by fix_scan_expr. */ foreach(l, splan->plan.targetlist) { TargetEntry *tle = (TargetEntry *) lfirst(l); Var *var = (Var *) tle->expr; if (var && IsA(var, Var) && var->varno == ROWID_VAR) tle->expr = (Expr *) makeNullConst(var->vartype, var->vartypmod, var->varcollid); } splan->plan.targetlist = fix_scan_list(root, splan->plan.targetlist, rtoffset, NUM_EXEC_TLIST(plan)); splan->plan.qual = fix_scan_list(root, splan->plan.qual, rtoffset, NUM_EXEC_QUAL(plan)); } /* resconstantqual can't contain any subplan variable refs */ splan->resconstantqual = fix_scan_expr(root, splan->resconstantqual, rtoffset, 1); } break; case T_ProjectSet: set_upper_references(root, plan, rtoffset); break; case T_ModifyTable: { ModifyTable *splan = (ModifyTable *) plan; Plan *subplan = outerPlan(splan); Assert(splan->plan.targetlist == NIL); Assert(splan->plan.qual == NIL); splan->withCheckOptionLists = fix_scan_list(root, splan->withCheckOptionLists, rtoffset, 1); if (splan->returningLists) { List *newRL = NIL; ListCell *lcrl, *lcrr; /* * Pass each per-resultrel returningList through * set_returning_clause_references(). */ Assert(list_length(splan->returningLists) == list_length(splan->resultRelations)); forboth(lcrl, splan->returningLists, lcrr, splan->resultRelations) { List *rlist = (List *) lfirst(lcrl); Index resultrel = lfirst_int(lcrr); 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 mostly for the use * of EXPLAIN; the executor won't execute that targetlist, * although it does use it to prepare the node's result * tuple slot. 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)); } /* * We treat ModifyTable with ON CONFLICT as a form of 'pseudo * join', where the inner side is the EXCLUDED tuple. * Therefore use fix_join_expr to setup the relevant variables * to INNER_VAR. We explicitly don't create any OUTER_VARs as * those are already used by RETURNING and it seems better to * be non-conflicting. */ if (splan->onConflictSet) { indexed_tlist *itlist; itlist = build_tlist_index(splan->exclRelTlist); splan->onConflictSet = fix_join_expr(root, splan->onConflictSet, NULL, itlist, linitial_int(splan->resultRelations), rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); splan->onConflictWhere = (Node *) fix_join_expr(root, (List *) splan->onConflictWhere, NULL, itlist, linitial_int(splan->resultRelations), rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); pfree(itlist); splan->exclRelTlist = fix_scan_list(root, splan->exclRelTlist, rtoffset, 1); } /* * The MERGE statement produces the target rows by performing * a right join between the target relation and the source * relation (which could be a plain relation or a subquery). * The INSERT and UPDATE actions of the MERGE statement * require access to the columns from the source relation. We * arrange things so that the source relation attributes are * available as INNER_VAR and the target relation attributes * are available from the scan tuple. */ if (splan->mergeActionLists != NIL) { List *newMJC = NIL; ListCell *lca, *lcj, *lcr; /* * Fix the targetList of individual action nodes so that * the so-called "source relation" Vars are referenced as * INNER_VAR. Note that for this to work correctly during * execution, the ecxt_innertuple must be set to the tuple * obtained by executing the subplan, which is what * constitutes the "source relation". * * We leave the Vars from the result relation (i.e. the * target relation) unchanged i.e. those Vars would be * picked from the scan slot. So during execution, we must * ensure that ecxt_scantuple is setup correctly to refer * to the tuple from the target relation. */ indexed_tlist *itlist; itlist = build_tlist_index(subplan->targetlist); forthree(lca, splan->mergeActionLists, lcj, splan->mergeJoinConditions, lcr, splan->resultRelations) { List *mergeActionList = lfirst(lca); Node *mergeJoinCondition = lfirst(lcj); Index resultrel = lfirst_int(lcr); foreach(l, mergeActionList) { MergeAction *action = (MergeAction *) lfirst(l); /* Fix targetList of each action. */ action->targetList = fix_join_expr(root, action->targetList, NULL, itlist, resultrel, rtoffset, NRM_EQUAL, NUM_EXEC_TLIST(plan)); /* Fix quals too. */ action->qual = (Node *) fix_join_expr(root, (List *) action->qual, NULL, itlist, resultrel, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); } /* Fix join condition too. */ mergeJoinCondition = (Node *) fix_join_expr(root, (List *) mergeJoinCondition, NULL, itlist, resultrel, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); newMJC = lappend(newMJC, mergeJoinCondition); } splan->mergeJoinConditions = newMJC; } splan->nominalRelation += rtoffset; if (splan->rootRelation) splan->rootRelation += rtoffset; splan->exclRelRTI += rtoffset; foreach(l, splan->resultRelations) { lfirst_int(l) += rtoffset; } foreach(l, splan->rowMarks) { PlanRowMark *rc = (PlanRowMark *) lfirst(l); rc->rti += rtoffset; rc->prti += rtoffset; } /* * Append this ModifyTable node's final result relation RT * index(es) to the global list for the plan. */ root->glob->resultRelations = list_concat(root->glob->resultRelations, splan->resultRelations); if (splan->rootRelation) { root->glob->resultRelations = lappend_int(root->glob->resultRelations, splan->rootRelation); } } break; case T_Append: /* Needs special treatment, see comments below */ return set_append_references(root, (Append *) plan, rtoffset); case T_MergeAppend: /* Needs special treatment, see comments below */ return set_mergeappend_references(root, (MergeAppend *) plan, rtoffset); 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; List *stripped_indextlist; ListCell *lc; /* * Vars in the plan node's targetlist, qual, and recheckqual must only * reference columns that the index AM can actually return. To ensure * this, remove non-returnable columns (which are marked as resjunk) from * the indexed tlist. We can just drop them because the indexed_tlist * machinery pays attention to TLE resnos, not physical list position. */ stripped_indextlist = NIL; foreach(lc, plan->indextlist) { TargetEntry *indextle = (TargetEntry *) lfirst(lc); if (!indextle->resjunk) stripped_indextlist = lappend(stripped_indextlist, indextle); } index_itlist = build_tlist_index(stripped_indextlist); plan->scan.scanrelid += rtoffset; plan->scan.plan.targetlist = (List *) fix_upper_expr(root, (Node *) plan->scan.plan.targetlist, index_itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_TLIST((Plan *) plan)); plan->scan.plan.qual = (List *) fix_upper_expr(root, (Node *) plan->scan.plan.qual, index_itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) plan)); plan->recheckqual = (List *) fix_upper_expr(root, (Node *) plan->recheckqual, index_itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) plan)); /* indexqual is already transformed to reference index columns */ plan->indexqual = fix_scan_list(root, plan->indexqual, rtoffset, 1); /* indexorderby is already transformed to reference index columns */ plan->indexorderby = fix_scan_list(root, plan->indexorderby, rtoffset, 1); /* indextlist must NOT be transformed to reference index columns */ plan->indextlist = fix_scan_list(root, plan->indextlist, rtoffset, NUM_EXEC_TLIST((Plan *) plan)); 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); /* 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. */ result = clean_up_removed_plan_level((Plan *) plan, plan->subplan); } 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, NUM_EXEC_TLIST((Plan *) plan)); plan->scan.plan.qual = fix_scan_list(root, plan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL((Plan *) plan)); 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. * * This can be called from mark_async_capable_plan(), a helper function for * create_append_plan(), before set_subqueryscan_references(), to determine * triviality of a SubqueryScan that is a child of an Append node. So we * cache the result in the SubqueryScan node to avoid repeated computation. * * Note: when called from mark_async_capable_plan(), we determine the result * before running finalize_plan() on the SubqueryScan node (if needed) and * set_plan_references() on the subplan tree, but this would be safe, because * 1) finalize_plan() doesn't modify the tlist or quals for the SubqueryScan * node (or that for any plan node in the subplan tree), and * 2) set_plan_references() modifies the tlist for every plan node in the * subplan tree, but keeps const/resjunk columns as const/resjunk ones and * preserves the length and order of the tlist, and * 3) set_plan_references() might delete the topmost plan node like an Append * or MergeAppend from the subplan tree and pull up the child plan node, * but in that case, the tlist for the child plan node exactly matches the * parent. */ bool trivial_subqueryscan(SubqueryScan *plan) { int attrno; ListCell *lp, *lc; /* We might have detected this already; in which case reuse the result */ if (plan->scanstatus == SUBQUERY_SCAN_TRIVIAL) return true; if (plan->scanstatus == SUBQUERY_SCAN_NONTRIVIAL) return false; Assert(plan->scanstatus == SUBQUERY_SCAN_UNKNOWN); /* Initially, mark the SubqueryScan as non-deletable from the plan tree */ plan->scanstatus = SUBQUERY_SCAN_NONTRIVIAL; 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++; } /* Re-mark the SubqueryScan as deletable from the plan tree */ plan->scanstatus = SUBQUERY_SCAN_TRIVIAL; return true; } /* * clean_up_removed_plan_level * Do necessary cleanup when we strip out a SubqueryScan, Append, etc * * We are dropping the "parent" plan in favor of returning just its "child". * A few small tweaks are needed. */ static Plan * clean_up_removed_plan_level(Plan *parent, Plan *child) { /* * We have to be sure we don't lose any initplans, so move any that were * attached to the parent plan to the child. If any are parallel-unsafe, * the child is no longer parallel-safe. As a cosmetic matter, also add * the initplans' run costs to the child's costs. */ if (parent->initPlan) { Cost initplan_cost; bool unsafe_initplans; SS_compute_initplan_cost(parent->initPlan, &initplan_cost, &unsafe_initplans); child->startup_cost += initplan_cost; child->total_cost += initplan_cost; if (unsafe_initplans) child->parallel_safe = false; /* * Attach plans this way so that parent's initplans are processed * before any pre-existing initplans of the child. Probably doesn't * matter, but let's preserve the ordering just in case. */ child->initPlan = list_concat(parent->initPlan, child->initPlan); } /* * We also have to transfer the parent's column labeling info into the * child, else columns sent to client will be improperly labeled if this * is the topmost plan level. resjunk and so on may be important too. */ apply_tlist_labeling(child->targetlist, parent->targetlist); return child; } /* * set_foreignscan_references * Do set_plan_references processing on a ForeignScan */ static void set_foreignscan_references(PlannerInfo *root, ForeignScan *fscan, int rtoffset) { /* Adjust scanrelid if it's valid */ if (fscan->scan.scanrelid > 0) fscan->scan.scanrelid += rtoffset; if (fscan->fdw_scan_tlist != NIL || fscan->scan.scanrelid == 0) { /* * Adjust tlist, qual, fdw_exprs, fdw_recheck_quals to reference * foreign scan tuple */ indexed_tlist *itlist = build_tlist_index(fscan->fdw_scan_tlist); fscan->scan.plan.targetlist = (List *) fix_upper_expr(root, (Node *) fscan->scan.plan.targetlist, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_TLIST((Plan *) fscan)); fscan->scan.plan.qual = (List *) fix_upper_expr(root, (Node *) fscan->scan.plan.qual, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) fscan)); fscan->fdw_exprs = (List *) fix_upper_expr(root, (Node *) fscan->fdw_exprs, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) fscan)); fscan->fdw_recheck_quals = (List *) fix_upper_expr(root, (Node *) fscan->fdw_recheck_quals, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) fscan)); pfree(itlist); /* fdw_scan_tlist itself just needs fix_scan_list() adjustments */ fscan->fdw_scan_tlist = fix_scan_list(root, fscan->fdw_scan_tlist, rtoffset, NUM_EXEC_TLIST((Plan *) fscan)); } else { /* * Adjust tlist, qual, fdw_exprs, fdw_recheck_quals in the standard * way */ fscan->scan.plan.targetlist = fix_scan_list(root, fscan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST((Plan *) fscan)); fscan->scan.plan.qual = fix_scan_list(root, fscan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL((Plan *) fscan)); fscan->fdw_exprs = fix_scan_list(root, fscan->fdw_exprs, rtoffset, NUM_EXEC_QUAL((Plan *) fscan)); fscan->fdw_recheck_quals = fix_scan_list(root, fscan->fdw_recheck_quals, rtoffset, NUM_EXEC_QUAL((Plan *) fscan)); } fscan->fs_relids = offset_relid_set(fscan->fs_relids, rtoffset); fscan->fs_base_relids = offset_relid_set(fscan->fs_base_relids, rtoffset); /* Adjust resultRelation if it's valid */ if (fscan->resultRelation > 0) fscan->resultRelation += rtoffset; } /* * set_customscan_references * Do set_plan_references processing on a CustomScan */ static void set_customscan_references(PlannerInfo *root, CustomScan *cscan, int rtoffset) { ListCell *lc; /* Adjust scanrelid if it's valid */ if (cscan->scan.scanrelid > 0) cscan->scan.scanrelid += rtoffset; if (cscan->custom_scan_tlist != NIL || cscan->scan.scanrelid == 0) { /* Adjust tlist, qual, custom_exprs to reference custom scan tuple */ indexed_tlist *itlist = build_tlist_index(cscan->custom_scan_tlist); cscan->scan.plan.targetlist = (List *) fix_upper_expr(root, (Node *) cscan->scan.plan.targetlist, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_TLIST((Plan *) cscan)); cscan->scan.plan.qual = (List *) fix_upper_expr(root, (Node *) cscan->scan.plan.qual, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) cscan)); cscan->custom_exprs = (List *) fix_upper_expr(root, (Node *) cscan->custom_exprs, itlist, INDEX_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) cscan)); pfree(itlist); /* custom_scan_tlist itself just needs fix_scan_list() adjustments */ cscan->custom_scan_tlist = fix_scan_list(root, cscan->custom_scan_tlist, rtoffset, NUM_EXEC_TLIST((Plan *) cscan)); } else { /* Adjust tlist, qual, custom_exprs in the standard way */ cscan->scan.plan.targetlist = fix_scan_list(root, cscan->scan.plan.targetlist, rtoffset, NUM_EXEC_TLIST((Plan *) cscan)); cscan->scan.plan.qual = fix_scan_list(root, cscan->scan.plan.qual, rtoffset, NUM_EXEC_QUAL((Plan *) cscan)); cscan->custom_exprs = fix_scan_list(root, cscan->custom_exprs, rtoffset, NUM_EXEC_QUAL((Plan *) cscan)); } /* Adjust child plan-nodes recursively, if needed */ foreach(lc, cscan->custom_plans) { lfirst(lc) = set_plan_refs(root, (Plan *) lfirst(lc), rtoffset); } cscan->custom_relids = offset_relid_set(cscan->custom_relids, rtoffset); } /* * register_partpruneinfo * Subroutine for set_append_references and set_mergeappend_references * * Add the PartitionPruneInfo from root->partPruneInfos at the given index * into PlannerGlobal->partPruneInfos and return its index there. * * Also update the RT indexes present in PartitionedRelPruneInfos to add the * offset. * * Finally, if there are initial pruning steps, add the RT indexes of the * leaf partitions to the set of relations that are prunable at execution * startup time. */ static int register_partpruneinfo(PlannerInfo *root, int part_prune_index, int rtoffset) { PlannerGlobal *glob = root->glob; PartitionPruneInfo *pinfo; ListCell *l; Assert(part_prune_index >= 0 && part_prune_index < list_length(root->partPruneInfos)); pinfo = list_nth_node(PartitionPruneInfo, root->partPruneInfos, part_prune_index); pinfo->relids = offset_relid_set(pinfo->relids, rtoffset); foreach(l, pinfo->prune_infos) { List *prune_infos = lfirst(l); ListCell *l2; foreach(l2, prune_infos) { PartitionedRelPruneInfo *prelinfo = lfirst(l2); int i; prelinfo->rtindex += rtoffset; prelinfo->initial_pruning_steps = fix_scan_list(root, prelinfo->initial_pruning_steps, rtoffset, 1); prelinfo->exec_pruning_steps = fix_scan_list(root, prelinfo->exec_pruning_steps, rtoffset, 1); for (i = 0; i < prelinfo->nparts; i++) { /* * Non-leaf partitions and partitions that do not have a * subplan are not included in this map as mentioned in * make_partitionedrel_pruneinfo(). */ if (prelinfo->leafpart_rti_map[i]) { prelinfo->leafpart_rti_map[i] += rtoffset; if (prelinfo->initial_pruning_steps) glob->prunableRelids = bms_add_member(glob->prunableRelids, prelinfo->leafpart_rti_map[i]); } } } } glob->partPruneInfos = lappend(glob->partPruneInfos, pinfo); return list_length(glob->partPruneInfos) - 1; } /* * set_append_references * Do set_plan_references processing on an Append * * We try to strip out the Append entirely; if we can't, we have * to do the normal processing on it. */ static Plan * set_append_references(PlannerInfo *root, Append *aplan, int rtoffset) { ListCell *l; /* * Append, like Sort et al, doesn't actually evaluate its targetlist or * check quals. If it's got exactly one child plan, then it's not doing * anything useful at all, and we can strip it out. */ Assert(aplan->plan.qual == NIL); /* First, we gotta recurse on the children */ foreach(l, aplan->appendplans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } /* * See if it's safe to get rid of the Append entirely. For this to be * safe, there must be only one child plan and that child plan's parallel * awareness must match the Append's. The reason for the latter is that * if the Append is parallel aware and the child is not, then the calling * plan may execute the non-parallel aware child multiple times. (If you * change these rules, update create_append_path to match.) */ if (list_length(aplan->appendplans) == 1) { Plan *p = (Plan *) linitial(aplan->appendplans); if (p->parallel_aware == aplan->plan.parallel_aware) return clean_up_removed_plan_level((Plan *) aplan, p); } /* * Otherwise, clean up the Append as needed. It's okay to do this after * recursing to the children, because set_dummy_tlist_references doesn't * look at those. */ set_dummy_tlist_references((Plan *) aplan, rtoffset); aplan->apprelids = offset_relid_set(aplan->apprelids, rtoffset); /* * Add PartitionPruneInfo, if any, to PlannerGlobal and update the index. * Also update the RT indexes present in it to add the offset. */ if (aplan->part_prune_index >= 0) aplan->part_prune_index = register_partpruneinfo(root, aplan->part_prune_index, rtoffset); /* We don't need to recurse to lefttree or righttree ... */ Assert(aplan->plan.lefttree == NULL); Assert(aplan->plan.righttree == NULL); return (Plan *) aplan; } /* * set_mergeappend_references * Do set_plan_references processing on a MergeAppend * * We try to strip out the MergeAppend entirely; if we can't, we have * to do the normal processing on it. */ static Plan * set_mergeappend_references(PlannerInfo *root, MergeAppend *mplan, int rtoffset) { ListCell *l; /* * MergeAppend, like Sort et al, doesn't actually evaluate its targetlist * or check quals. If it's got exactly one child plan, then it's not * doing anything useful at all, and we can strip it out. */ Assert(mplan->plan.qual == NIL); /* First, we gotta recurse on the children */ foreach(l, mplan->mergeplans) { lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset); } /* * See if it's safe to get rid of the MergeAppend entirely. For this to * be safe, there must be only one child plan and that child plan's * parallel awareness must match the MergeAppend's. The reason for the * latter is that if the MergeAppend is parallel aware and the child is * not, then the calling plan may execute the non-parallel aware child * multiple times. (If you change these rules, update * create_merge_append_path to match.) */ if (list_length(mplan->mergeplans) == 1) { Plan *p = (Plan *) linitial(mplan->mergeplans); if (p->parallel_aware == mplan->plan.parallel_aware) return clean_up_removed_plan_level((Plan *) mplan, p); } /* * Otherwise, clean up the MergeAppend as needed. It's okay to do this * after recursing to the children, because set_dummy_tlist_references * doesn't look at those. */ set_dummy_tlist_references((Plan *) mplan, rtoffset); mplan->apprelids = offset_relid_set(mplan->apprelids, rtoffset); /* * Add PartitionPruneInfo, if any, to PlannerGlobal and update the index. * Also update the RT indexes present in it to add the offset. */ if (mplan->part_prune_index >= 0) mplan->part_prune_index = register_partpruneinfo(root, mplan->part_prune_index, rtoffset); /* We don't need to recurse to lefttree or righttree ... */ Assert(mplan->plan.lefttree == NULL); Assert(mplan->plan.righttree == NULL); return (Plan *) mplan; } /* * set_hash_references * Do set_plan_references processing on a Hash node */ static void set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset) { Hash *hplan = (Hash *) plan; Plan *outer_plan = plan->lefttree; indexed_tlist *outer_itlist; /* * Hash's hashkeys are used when feeding tuples into the hashtable, * therefore have them reference Hash's outer plan (which itself is the * inner plan of the HashJoin). */ outer_itlist = build_tlist_index(outer_plan->targetlist); hplan->hashkeys = (List *) fix_upper_expr(root, (Node *) hplan->hashkeys, outer_itlist, OUTER_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan)); /* Hash doesn't project */ set_dummy_tlist_references(plan, rtoffset); /* Hash nodes don't have their own quals */ Assert(plan->qual == NIL); } /* * offset_relid_set * Apply rtoffset to the members of a Relids set. */ static Relids offset_relid_set(Relids relids, int rtoffset) { Relids result = NULL; int rtindex; /* If there's no offset to apply, we needn't recompute the value */ if (rtoffset == 0) return relids; rtindex = -1; while ((rtindex = bms_next_member(relids, rtindex)) >= 0) result = bms_add_member(result, rtindex + rtoffset); return result; } /* * 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 PlanInvalItems for user-defined functions into root->glob->invalItems. * We also fill in column index lists for GROUPING() expressions. * * 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)) { ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) node; set_sa_opfuncid(saop); record_plan_function_dependency(root, saop->opfuncid); if (OidIsValid(saop->hashfuncid)) record_plan_function_dependency(root, saop->hashfuncid); if (OidIsValid(saop->negfuncid)) record_plan_function_dependency(root, saop->negfuncid); } 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)); } else if (IsA(node, GroupingFunc)) { GroupingFunc *g = (GroupingFunc *) node; AttrNumber *grouping_map = root->grouping_map; /* If there are no grouping sets, we don't need this. */ Assert(grouping_map || g->cols == NIL); if (grouping_map) { ListCell *lc; List *cols = NIL; foreach(lc, g->refs) { cols = lappend_int(cols, grouping_map[lfirst_int(lc)]); } Assert(!g->cols || equal(cols, g->cols)); if (!g->cols) g->cols = cols; } } } /* * 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 (Node *) copyObject(p); } /* * fix_alternative_subplan * Do set_plan_references processing on an AlternativeSubPlan * * Choose one of the alternative implementations and return just that one, * discarding the rest of the AlternativeSubPlan structure. * Note: caller must still recurse into the result! * * We don't make any attempt to fix up cost estimates in the parent plan * node or higher-level nodes. */ static Node * fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan, double num_exec) { SubPlan *bestplan = NULL; Cost bestcost = 0; ListCell *lc; /* * Compute the estimated cost of each subplan assuming num_exec * executions, and keep the cheapest one. In event of exact equality of * estimates, we prefer the later plan; this is a bit arbitrary, but in * current usage it biases us to break ties against fast-start subplans. */ Assert(asplan->subplans != NIL); foreach(lc, asplan->subplans) { SubPlan *curplan = (SubPlan *) lfirst(lc); Cost curcost; curcost = curplan->startup_cost + num_exec * curplan->per_call_cost; if (bestplan == NULL || curcost <= bestcost) { bestplan = curplan; bestcost = curcost; } /* Also mark all subplans that are in AlternativeSubPlans */ root->isAltSubplan[curplan->plan_id - 1] = true; } /* Mark the subplan we selected */ root->isUsedSubplan[bestplan->plan_id - 1] = true; return (Node *) bestplan; } /* * 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, * replacing Aggref nodes that should be replaced by initplan output Params, * choosing the best implementation for AlternativeSubPlans, * looking up operator opcode info for OpExpr and related nodes, * and adding OIDs from regclass Const nodes into root->glob->relationOids. * * 'node': the expression to be modified * 'rtoffset': how much to increment varnos by * 'num_exec': estimated number of executions of expression * * The expression tree is either copied-and-modified, or modified in-place * if that seems safe. */ static Node * fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec) { fix_scan_expr_context context; context.root = root; context.rtoffset = rtoffset; context.num_exec = num_exec; if (rtoffset != 0 || root->multiexpr_params != NIL || root->glob->lastPHId != 0 || root->minmax_aggs != NIL || root->hasAlternativeSubPlans) { 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, and if there are no minmax Aggrefs we * won't need to replace them, and if there are no AlternativeSubPlans * 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 Vars marked INNER_VAR, OUTER_VAR, or ROWID_VAR. * But an indexqual expression could contain INDEX_VAR Vars. */ Assert(var->varno != INNER_VAR); Assert(var->varno != OUTER_VAR); Assert(var->varno != ROWID_VAR); if (!IS_SPECIAL_VARNO(var->varno)) var->varno += context->rtoffset; if (var->varnosyn > 0) var->varnosyn += context->rtoffset; return (Node *) var; } if (IsA(node, Param)) return fix_param_node(context->root, (Param *) node); if (IsA(node, Aggref)) { Aggref *aggref = (Aggref *) node; Param *aggparam; /* See if the Aggref should be replaced by a Param */ aggparam = find_minmax_agg_replacement_param(context->root, aggref); if (aggparam != NULL) { /* Make a copy of the Param for paranoia's sake */ return (Node *) copyObject(aggparam); } /* If no match, just fall through to process it normally */ } if (IsA(node, CurrentOfExpr)) { CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node); Assert(!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; /* XXX can we assert something about phnullingrels? */ return fix_scan_expr_mutator((Node *) phv->phexpr, context); } if (IsA(node, AlternativeSubPlan)) return fix_scan_expr_mutator(fix_alternative_subplan(context->root, (AlternativeSubPlan *) node, context->num_exec), context); fix_expr_common(context->root, node); return expression_tree_mutator(node, fix_scan_expr_mutator, context); } static bool fix_scan_expr_walker(Node *node, fix_scan_expr_context *context) { if (node == NULL) return false; Assert(!(IsA(node, Var) && ((Var *) node)->varno == ROWID_VAR)); Assert(!IsA(node, PlaceHolderVar)); Assert(!IsA(node, AlternativeSubPlan)); fix_expr_common(context->root, node); return expression_tree_walker(node, fix_scan_expr_walker, 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); /* * First process the joinquals (including merge or hash clauses). These * are logically below the join so they can always use all values * available from the input tlists. It's okay to also handle * NestLoopParams now, because those couldn't refer to nullable * subexpressions. */ join->joinqual = fix_join_expr(root, join->joinqual, outer_itlist, inner_itlist, (Index) 0, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) join)); /* 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); /* * Because we don't reparameterize parameterized paths to match * the outer-join level at which they are used, Vars seen in the * NestLoopParam expression may have nullingrels that are just a * subset of those in the Vars actually available from the outer * side. (Lateral references can also cause this, as explained in * the comments for identify_current_nestloop_params.) Not * checking this exactly is a bit grotty, but the work needed to * make things match up perfectly seems well out of proportion to * the value. */ nlp->paramval = (Var *) fix_upper_expr(root, (Node *) nlp->paramval, outer_itlist, OUTER_VAR, rtoffset, NRM_SUBSET, NUM_EXEC_TLIST(outer_plan)); /* 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, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) join)); } else if (IsA(join, HashJoin)) { HashJoin *hj = (HashJoin *) join; hj->hashclauses = fix_join_expr(root, hj->hashclauses, outer_itlist, inner_itlist, (Index) 0, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) join)); /* * HashJoin's hashkeys are used to look for matching tuples from its * outer plan (not the Hash node!) in the hashtable. */ hj->hashkeys = (List *) fix_upper_expr(root, (Node *) hj->hashkeys, outer_itlist, OUTER_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_QUAL((Plan *) join)); } /* * Now we need to fix up the targetlist and qpqual, which are logically * above the join. This means that, if it's not an inner join, any Vars * and PHVs appearing here should have nullingrels that include the * effects of the outer join, ie they will have nullingrels equal to the * input Vars' nullingrels plus the bit added by the outer join. We don't * currently have enough info available here to identify what that should * be, so we just tell fix_join_expr to accept superset nullingrels * matches instead of exact ones. */ join->plan.targetlist = fix_join_expr(root, join->plan.targetlist, outer_itlist, inner_itlist, (Index) 0, rtoffset, (join->jointype == JOIN_INNER ? NRM_EQUAL : NRM_SUPERSET), NUM_EXEC_TLIST((Plan *) join)); join->plan.qual = fix_join_expr(root, join->plan.qual, outer_itlist, inner_itlist, (Index) 0, rtoffset, (join->jointype == JOIN_INNER ? NRM_EQUAL : NRM_SUPERSET), NUM_EXEC_QUAL((Plan *) join)); 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 flattening these selfsame expressions, so it should have all * the required variables). There is an important exception, however: * depending on where we are in the plan tree, sort/group columns may 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); /* * If it's a grouping node with grouping sets, any Vars and PHVs appearing * in the targetlist and quals should have nullingrels that include the * effects of the grouping step, ie they will have nullingrels equal to * the input Vars/PHVs' nullingrels plus the RT index of the grouping * step. In order to perform exact nullingrels matches, we remove the RT * index of the grouping step first. */ if (IsA(plan, Agg) && root->group_rtindex > 0 && ((Agg *) plan)->groupingSets) { plan->targetlist = (List *) remove_nulling_relids((Node *) plan->targetlist, bms_make_singleton(root->group_rtindex), NULL); plan->qual = (List *) remove_nulling_relids((Node *) plan->qual, bms_make_singleton(root->group_rtindex), NULL); } output_targetlist = NIL; foreach(l, plan->targetlist) { TargetEntry *tle = (TargetEntry *) lfirst(l); Node *newexpr; /* If it's a sort/group item, first try to match by sortref */ if (tle->ressortgroupref != 0) { newexpr = (Node *) search_indexed_tlist_for_sortgroupref(tle->expr, tle->ressortgroupref, subplan_itlist, OUTER_VAR); if (!newexpr) newexpr = fix_upper_expr(root, (Node *) tle->expr, subplan_itlist, OUTER_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_TLIST(plan)); } else newexpr = fix_upper_expr(root, (Node *) tle->expr, subplan_itlist, OUTER_VAR, rtoffset, NRM_EQUAL, NUM_EXEC_TLIST(plan)); 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, NRM_EQUAL, NUM_EXEC_QUAL(plan)); pfree(subplan_itlist); } /* * set_param_references * Initialize the initParam list in Gather or Gather merge node such that * it contains reference of all the params that needs to be evaluated * before execution of the node. It contains the initplan params that are * being passed to the plan nodes below it. */ static void set_param_references(PlannerInfo *root, Plan *plan) { Assert(IsA(plan, Gather) || IsA(plan, GatherMerge)); if (plan->lefttree->extParam) { PlannerInfo *proot; Bitmapset *initSetParam = NULL; ListCell *l; for (proot = root; proot != NULL; proot = proot->parent_root) { foreach(l, proot->init_plans) { SubPlan *initsubplan = (SubPlan *) lfirst(l); ListCell *l2; foreach(l2, initsubplan->setParam) { initSetParam = bms_add_member(initSetParam, lfirst_int(l2)); } } } /* * Remember the list of all external initplan params that are used by * the children of Gather or Gather merge node. */ if (IsA(plan, Gather)) ((Gather *) plan)->initParam = bms_intersect(plan->lefttree->extParam, initSetParam); else ((GatherMerge *) plan)->initParam = bms_intersect(plan->lefttree->extParam, initSetParam); } } /* * Recursively scan an expression tree and convert Aggrefs to the proper * intermediate form for combining aggregates. This means (1) replacing each * one's argument list with a single argument that is the original Aggref * modified to show partial aggregation and (2) changing the upper Aggref to * show combining aggregation. * * After this step, set_upper_references will replace the partial Aggrefs * with Vars referencing the lower Agg plan node's outputs, so that the final * form seen by the executor is a combining Aggref with a Var as input. * * It's rather messy to postpone this step until setrefs.c; ideally it'd be * done in createplan.c. The difficulty is that once we modify the Aggref * expressions, they will no longer be equal() to their original form and * so cross-plan-node-level matches will fail. So this has to happen after * the plan node above the Agg has resolved its subplan references. */ static Node * convert_combining_aggrefs(Node *node, void *context) { if (node == NULL) return NULL; if (IsA(node, Aggref)) { Aggref *orig_agg = (Aggref *) node; Aggref *child_agg; Aggref *parent_agg; /* Assert we've not chosen to partial-ize any unsupported cases */ Assert(orig_agg->aggorder == NIL); Assert(orig_agg->aggdistinct == NIL); /* * Since aggregate calls can't be nested, we needn't recurse into the * arguments. But for safety, flat-copy the Aggref node itself rather * than modifying it in-place. */ child_agg = makeNode(Aggref); memcpy(child_agg, orig_agg, sizeof(Aggref)); /* * For the parent Aggref, we want to copy all the fields of the * original aggregate *except* the args list, which we'll replace * below, and the aggfilter expression, which should be applied only * by the child not the parent. Rather than explicitly knowing about * all the other fields here, we can momentarily modify child_agg to * provide a suitable source for copyObject. */ child_agg->args = NIL; child_agg->aggfilter = NULL; parent_agg = copyObject(child_agg); child_agg->args = orig_agg->args; child_agg->aggfilter = orig_agg->aggfilter; /* * Now, set up child_agg to represent the first phase of partial * aggregation. For now, assume serialization is required. */ mark_partial_aggref(child_agg, AGGSPLIT_INITIAL_SERIAL); /* * And set up parent_agg to represent the second phase. */ parent_agg->args = list_make1(makeTargetEntry((Expr *) child_agg, 1, NULL, false)); mark_partial_aggref(parent_agg, AGGSPLIT_FINAL_DESERIAL); return (Node *) parent_agg; } return expression_tree_mutator(node, convert_combining_aggrefs, context); } /* * 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; /* * As in search_indexed_tlist_for_non_var(), we prefer to keep Consts * as Consts, not Vars referencing Consts. Here, there's no speed * advantage to be had, but it makes EXPLAIN output look cleaner, and * again it avoids confusing the executor. */ if (IsA(oldvar, Const)) { /* just reuse the existing TLE node */ output_targetlist = lappend(output_targetlist, tle); continue; } newvar = makeVar(OUTER_VAR, tle->resno, exprType((Node *) oldvar), exprTypmod((Node *) oldvar), exprCollation((Node *) oldvar), 0); if (IsA(oldvar, Var) && oldvar->varnosyn > 0) { newvar->varnosyn = oldvar->varnosyn + rtoffset; newvar->varattnosyn = oldvar->varattnosyn; } else { newvar->varnosyn = 0; /* wasn't ever a plain Var */ newvar->varattnosyn = 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() and siblings. * 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->varnullingrels = var->varnullingrels; 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, int 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->varnullingrels = var->varnullingrels; 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 varnosyn is incremented by rtoffset. * If no match, return NULL. * * We cross-check the varnullingrels of the subplan output Var based on * nrm_match. Most call sites should pass NRM_EQUAL indicating we expect * an exact match. However, there are places where we haven't cleaned * things up completely, and we have to settle for allowing subset or * superset matches. */ static Var * search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist, int newvarno, int rtoffset, NullingRelsMatch nrm_match) { int 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); /* * Verify that we kept all the nullingrels machinations straight. * * XXX we skip the check for system columns and whole-row Vars. * That's because such Vars might be row identity Vars, which are * generated without any varnullingrels. It'd be hard to do * otherwise, since they're normally made very early in planning, * when we haven't looked at the jointree yet and don't know which * joins might null such Vars. Doesn't seem worth the expense to * make them fully valid. (While it's slightly annoying that we * thereby lose checking for user-written references to such * columns, it seems unlikely that a bug in nullingrels logic * would affect only system columns.) */ if (!(varattno <= 0 || (nrm_match == NRM_SUBSET ? bms_is_subset(var->varnullingrels, vinfo->varnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(vinfo->varnullingrels, var->varnullingrels) : bms_equal(vinfo->varnullingrels, var->varnullingrels)))) elog(ERROR, "wrong varnullingrels %s (expected %s) for Var %d/%d", bmsToString(var->varnullingrels), bmsToString(vinfo->varnullingrels), varno, varattno); newvar->varno = newvarno; newvar->varattno = vinfo->resno; if (newvar->varnosyn > 0) newvar->varnosyn += rtoffset; return newvar; } vinfo++; } return NULL; /* no match */ } /* * search_indexed_tlist_for_phv --- find a PlaceHolderVar in an indexed tlist * * If a match is found, return a Var constructed to reference the tlist item. * If no match, return NULL. * * Cross-check phnullingrels as in search_indexed_tlist_for_var. * * NOTE: it is a waste of time to call this unless itlist->has_ph_vars. */ static Var * search_indexed_tlist_for_phv(PlaceHolderVar *phv, indexed_tlist *itlist, int newvarno, NullingRelsMatch nrm_match) { ListCell *lc; foreach(lc, itlist->tlist) { TargetEntry *tle = (TargetEntry *) lfirst(lc); if (tle->expr && IsA(tle->expr, PlaceHolderVar)) { PlaceHolderVar *subphv = (PlaceHolderVar *) tle->expr; Var *newvar; /* * Analogously to search_indexed_tlist_for_var, we match on phid * only. We don't use equal(), partially for speed but mostly * because phnullingrels might not be exactly equal. */ if (phv->phid != subphv->phid) continue; /* Verify that we kept all the nullingrels machinations straight */ if (!(nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingrels, phv->phnullingrels))) elog(ERROR, "wrong phnullingrels %s (expected %s) for PlaceHolderVar %d", bmsToString(phv->phnullingrels), bmsToString(subphv->phnullingrels), phv->phid); /* Found a matching subplan output expression */ newvar = makeVarFromTargetEntry(newvarno, tle); newvar->varnosyn = 0; /* wasn't ever a plain Var */ newvar->varattnosyn = 0; return newvar; } } return NULL; /* no match */ } /* * search_indexed_tlist_for_non_var --- find a non-Var/PHV 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_non_vars. */ static Var * search_indexed_tlist_for_non_var(Expr *node, indexed_tlist *itlist, int newvarno) { TargetEntry *tle; /* * If it's a simple Const, replacing it with a Var is silly, even if there * happens to be an identical Const below; a Var is more expensive to * execute than a Const. What's more, replacing it could confuse some * places in the executor that expect to see simple Consts for, eg, * dropped columns. */ if (IsA(node, Const)) return NULL; tle = tlist_member(node, itlist->tlist); if (tle) { /* Found a matching subplan output expression */ Var *newvar; newvar = makeVarFromTargetEntry(newvarno, tle); newvar->varnosyn = 0; /* wasn't ever a plain Var */ newvar->varattnosyn = 0; return newvar; } return NULL; /* no match */ } /* * search_indexed_tlist_for_sortgroupref --- find a sort/group expression * * 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(Expr *node, Index sortgroupref, indexed_tlist *itlist, int newvarno) { ListCell *lc; foreach(lc, itlist->tlist) { TargetEntry *tle = (TargetEntry *) lfirst(lc); /* * Usually the equal() check is redundant, but in setop plans it may * not be, since prepunion.c assigns ressortgroupref equal to the * column resno without regard to whether that matches the topmost * level's sortgrouprefs and without regard to whether any implicit * coercions are added in the setop tree. We might have to clean that * up someday; but for now, just ignore any false matches. */ if (tle->ressortgroupref == sortgroupref && equal(node, tle->expr)) { /* Found a matching subplan output expression */ Var *newvar; newvar = makeVarFromTargetEntry(newvarno, tle); newvar->varnosyn = 0; /* wasn't ever a plain Var */ newvar->varattnosyn = 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 four different scenarios: * 1) a normal join clause, where all the Vars in the clause *must* be * replaced by OUTER_VAR or INNER_VAR references. In this case * acceptable_rel should be zero so that any failure to match a Var will be * reported as an error. * 2) RETURNING clauses, which may contain both Vars of the target relation * and Vars of other relations. In this case we want to replace the * other-relation Vars by OUTER_VAR references, while leaving target Vars * alone. Thus inner_itlist = NULL and acceptable_rel = the ID of the * target relation should be passed. * 3) ON CONFLICT UPDATE SET/WHERE clauses. Here references to EXCLUDED are * to be replaced with INNER_VAR references, while leaving target Vars (the * to-be-updated relation) alone. Correspondingly inner_itlist is to be * EXCLUDED elements, outer_itlist = NULL and acceptable_rel the target * relation. * 4) MERGE. In this case, references to the source relation are to be * replaced with INNER_VAR references, leaving Vars of the target * relation (the to-be-modified relation) alone. So inner_itlist is to be * the source relation elements, outer_itlist = NULL and acceptable_rel * the target relation. * * 'clauses' is the targetlist or list of join clauses * 'outer_itlist' is the indexed target list of the outer join relation, * or NULL * '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 varnos by * 'nrm_match': as for search_indexed_tlist_for_var() * 'num_exec': estimated number of executions of expression * * 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, NullingRelsMatch nrm_match, double num_exec) { 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; context.nrm_match = nrm_match; context.num_exec = num_exec; 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; /* * Verify that Vars with non-default varreturningtype only appear in * the RETURNING list, and refer to the target relation. */ if (var->varreturningtype != VAR_RETURNING_DEFAULT) { if (context->inner_itlist != NULL || context->outer_itlist == NULL || context->acceptable_rel == 0) elog(ERROR, "variable returning old/new found outside RETURNING list"); if (var->varno != context->acceptable_rel) elog(ERROR, "wrong varno %d (expected %d) for variable returning old/new", var->varno, context->acceptable_rel); } /* Look for the var in the input tlists, first in the outer */ if (context->outer_itlist) { newvar = search_indexed_tlist_for_var(var, context->outer_itlist, OUTER_VAR, context->rtoffset, context->nrm_match); if (newvar) return (Node *) newvar; } /* then in the inner. */ if (context->inner_itlist) { newvar = search_indexed_tlist_for_var(var, context->inner_itlist, INNER_VAR, context->rtoffset, context->nrm_match); 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->varnosyn > 0) var->varnosyn += 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 && context->outer_itlist->has_ph_vars) { newvar = search_indexed_tlist_for_phv(phv, context->outer_itlist, OUTER_VAR, context->nrm_match); if (newvar) return (Node *) newvar; } if (context->inner_itlist && context->inner_itlist->has_ph_vars) { newvar = search_indexed_tlist_for_phv(phv, context->inner_itlist, INNER_VAR, context->nrm_match); if (newvar) return (Node *) newvar; } /* If not supplied by input plans, evaluate the contained expr */ /* XXX can we assert something about phnullingrels? */ return fix_join_expr_mutator((Node *) phv->phexpr, context); } /* Try matching more complex expressions too, if tlists have any */ if (context->outer_itlist && context->outer_itlist->has_non_vars) { newvar = search_indexed_tlist_for_non_var((Expr *) 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((Expr *) node, context->inner_itlist, INNER_VAR); if (newvar) return (Node *) newvar; } /* Special cases (apply only AFTER failing to match to lower tlist) */ if (IsA(node, Param)) return fix_param_node(context->root, (Param *) node); if (IsA(node, AlternativeSubPlan)) return fix_join_expr_mutator(fix_alternative_subplan(context->root, (AlternativeSubPlan *) node, context->num_exec), context); fix_expr_common(context->root, node); return expression_tree_mutator(node, fix_join_expr_mutator, context); } /* * fix_upper_expr * Modifies an expression tree so that all Var nodes reference outputs * of a subplan. Also looks for Aggref nodes that should be replaced * by initplan output Params. 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 by flattening the expressions used in the * parent node. * * 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 varnos by * 'nrm_match': as for search_indexed_tlist_for_var() * 'num_exec': estimated number of executions of expression * * 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, int newvarno, int rtoffset, NullingRelsMatch nrm_match, double num_exec) { fix_upper_expr_context context; context.root = root; context.subplan_itlist = subplan_itlist; context.newvarno = newvarno; context.rtoffset = rtoffset; context.nrm_match = nrm_match; context.num_exec = num_exec; 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, context->nrm_match); 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_phv(phv, context->subplan_itlist, context->newvarno, context->nrm_match); if (newvar) return (Node *) newvar; } /* If not supplied by input plan, evaluate the contained expr */ /* XXX can we assert something about phnullingrels? */ return fix_upper_expr_mutator((Node *) phv->phexpr, context); } /* Try matching more complex expressions too, if tlist has any */ if (context->subplan_itlist->has_non_vars) { newvar = search_indexed_tlist_for_non_var((Expr *) node, context->subplan_itlist, context->newvarno); if (newvar) return (Node *) newvar; } /* Special cases (apply only AFTER failing to match to lower tlist) */ if (IsA(node, Param)) return fix_param_node(context->root, (Param *) node); if (IsA(node, Aggref)) { Aggref *aggref = (Aggref *) node; Param *aggparam; /* See if the Aggref should be replaced by a Param */ aggparam = find_minmax_agg_replacement_param(context->root, aggref); if (aggparam != NULL) { /* Make a copy of the Param for paranoia's sake */ return (Node *) copyObject(aggparam); } /* If no match, just fall through to process it normally */ } if (IsA(node, AlternativeSubPlan)) return fix_upper_expr_mutator(fix_alternative_subplan(context->root, (AlternativeSubPlan *) node, context->num_exec), context); fix_expr_common(context->root, node); return expression_tree_mutator(node, fix_upper_expr_mutator, 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, NRM_EQUAL, NUM_EXEC_TLIST(topplan)); pfree(itlist); return rlist; } /* * fix_windowagg_condition_expr_mutator * Mutator function for replacing WindowFuncs with the corresponding Var * in the targetlist which references that WindowFunc. */ static Node * fix_windowagg_condition_expr_mutator(Node *node, fix_windowagg_cond_context *context) { if (node == NULL) return NULL; if (IsA(node, WindowFunc)) { Var *newvar; newvar = search_indexed_tlist_for_non_var((Expr *) node, context->subplan_itlist, context->newvarno); if (newvar) return (Node *) newvar; elog(ERROR, "WindowFunc not found in subplan target lists"); } return expression_tree_mutator(node, fix_windowagg_condition_expr_mutator, context); } /* * fix_windowagg_condition_expr * Converts references in 'runcondition' so that any WindowFunc * references are swapped out for a Var which references the matching * WindowFunc in 'subplan_itlist'. */ static List * fix_windowagg_condition_expr(PlannerInfo *root, List *runcondition, indexed_tlist *subplan_itlist) { fix_windowagg_cond_context context; context.root = root; context.subplan_itlist = subplan_itlist; context.newvarno = 0; return (List *) fix_windowagg_condition_expr_mutator((Node *) runcondition, &context); } /* * set_windowagg_runcondition_references * Converts references in 'runcondition' so that any WindowFunc * references are swapped out for a Var which references the matching * WindowFunc in 'plan' targetlist. */ static List * set_windowagg_runcondition_references(PlannerInfo *root, List *runcondition, Plan *plan) { List *newlist; indexed_tlist *itlist; itlist = build_tlist_index(plan->targetlist); newlist = fix_windowagg_condition_expr(root, runcondition, itlist); pfree(itlist); return newlist; } /* * find_minmax_agg_replacement_param * If the given Aggref is one that we are optimizing into a subquery * (cf. planagg.c), then return the Param that should replace it. * Else return NULL. * * This is exported so that SS_finalize_plan can use it before setrefs.c runs. * Note that it will not find anything until we have built a Plan from a * MinMaxAggPath, as root->minmax_aggs will never be filled otherwise. */ Param * find_minmax_agg_replacement_param(PlannerInfo *root, Aggref *aggref) { if (root->minmax_aggs != NIL && list_length(aggref->args) == 1) { TargetEntry *curTarget = (TargetEntry *) linitial(aggref->args); ListCell *lc; foreach(lc, root->minmax_aggs) { MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc); if (mminfo->aggfnoid == aggref->aggfnoid && equal(mminfo->target, curTarget->expr)) return mminfo->param; } } return NULL; } /***************************************************************************** * 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 FirstUnpinnedObjectId. * Note that the OID generator guarantees never to generate such an OID * after startup, even at OID wraparound. */ if (funcid >= (Oid) FirstUnpinnedObjectId) { 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); } } /* * record_plan_type_dependency * Mark the current plan as depending on a particular type. * * This is exported so that eval_const_expressions can record a * dependency on a domain that it's removed a CoerceToDomain node for. * * We don't currently need to record dependencies on domains that the * plan contains CoerceToDomain nodes for, though that might change in * future. Hence, this isn't actually called in this module, though * someday fix_expr_common might call it. */ void record_plan_type_dependency(PlannerInfo *root, Oid typid) { /* * As in record_plan_function_dependency, ignore the possibility that * someone would change a built-in domain. */ if (typid >= (Oid) FirstUnpinnedObjectId) { PlanInvalItem *inval_item = makeNode(PlanInvalItem); /* * It would work to use any syscache on pg_type, but the easiest is * TYPEOID since we already have the type's OID at hand. Note that * plancache.c knows we use TYPEOID. */ inval_item->cacheId = TYPEOID; inval_item->hashValue = GetSysCacheHashValue1(TYPEOID, ObjectIdGetDatum(typid)); root->glob->invalItems = lappend(root->glob->invalItems, inval_item); } } /* * extract_query_dependencies * Given a rewritten, but 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. Also detect whether any * rewrite steps were affected by RLS. * * This is needed by plancache.c to handle invalidation of cached unplanned * queries. * * Note: this does not go through eval_const_expressions, and hence doesn't * reflect its additions of inlined functions and elided CoerceToDomain nodes * to the invalItems list. This is obviously OK for functions, since we'll * see them in the original query tree anyway. For domains, it's OK because * we don't care about domains unless they get elided. That is, a plan might * have domain dependencies that the query tree doesn't. */ 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; /* Hack: we use glob.dependsOnRole to collect hasRowSecurity flags */ glob.dependsOnRole = 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.dependsOnRole; } /* * Tree walker for extract_query_dependencies. * * This is exported so that expression_planner_with_deps can call it on * simple expressions (post-planning, not before planning, in that case). * In that usage, glob.dependsOnRole isn't meaningful, but the relationOids * and invalItems lists are added to as needed. */ bool extract_query_dependencies_walker(Node *node, PlannerInfo *context) { if (node == NULL) return false; Assert(!IsA(node, PlaceHolderVar)); if (IsA(node, Query)) { Query *query = (Query *) node; ListCell *lc; if (query->commandType == CMD_UTILITY) { /* * This logic must handle any utility command for which parse * analysis was nontrivial (cf. stmt_requires_parse_analysis). * * Notably, CALL requires its own processing. */ if (IsA(query->utilityStmt, CallStmt)) { CallStmt *callstmt = (CallStmt *) query->utilityStmt; /* We need not examine funccall, just the transformed exprs */ (void) extract_query_dependencies_walker((Node *) callstmt->funcexpr, context); (void) extract_query_dependencies_walker((Node *) callstmt->outargs, context); return false; } /* * Ignore other utility statements, except those (such as EXPLAIN) * that contain a parsed-but-not-planned query. For those, we * just need to transfer our attention to the contained query. */ query = UtilityContainsQuery(query->utilityStmt); if (query == NULL) return false; } /* Remember if any Query has RLS quals applied by rewriter */ if (query->hasRowSecurity) context->glob->dependsOnRole = true; /* Collect relation OIDs in this Query's rtable */ foreach(lc, query->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); if (rte->rtekind == RTE_RELATION || (rte->rtekind == RTE_SUBQUERY && OidIsValid(rte->relid)) || (rte->rtekind == RTE_NAMEDTUPLESTORE && OidIsValid(rte->relid))) 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, context, 0); } /* Extract function dependencies and check for regclass Consts */ fix_expr_common(context, node); return expression_tree_walker(node, extract_query_dependencies_walker, context); }