diff options
Diffstat (limited to 'src/backend/optimizer/plan/subselect.c')
| -rw-r--r-- | src/backend/optimizer/plan/subselect.c | 266 |
1 files changed, 140 insertions, 126 deletions
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index f3038cdffda..d0bc412c833 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -22,6 +22,7 @@ #include "nodes/nodeFuncs.h" #include "optimizer/clauses.h" #include "optimizer/cost.h" +#include "optimizer/pathnode.h" #include "optimizer/planmain.h" #include "optimizer/planner.h" #include "optimizer/prep.h" @@ -2048,60 +2049,38 @@ process_sublinks_mutator(Node *node, process_sublinks_context *context) } /* - * SS_finalize_plan - do final sublink and parameter processing for a - * completed Plan. + * SS_identify_outer_params - identify the Params available from outer levels * - * This recursively computes the extParam and allParam sets for every Plan - * node in the given plan tree. It also optionally attaches any previously - * generated InitPlans to the top plan node. (Any InitPlans should already - * have been put through SS_finalize_plan.) + * This must be run after SS_replace_correlation_vars and SS_process_sublinks + * processing is complete in a given query level as well as all of its + * descendant levels (which means it's most practical to do it at the end of + * processing the query level). We compute the set of paramIds that outer + * levels will make available to this level+descendants, and record it in + * root->outer_params for use while computing extParam/allParam sets in final + * plan cleanup. (We can't just compute it then, because the upper levels' + * plan_params lists are transient and will be gone by then.) */ void -SS_finalize_plan(PlannerInfo *root, Plan *plan, bool attach_initplans) +SS_identify_outer_params(PlannerInfo *root) { - Bitmapset *valid_params, - *initExtParam, - *initSetParam; - Cost initplan_cost; + Bitmapset *outer_params; PlannerInfo *proot; ListCell *l; /* - * Examine any initPlans to determine the set of external params they - * reference, the set of output params they supply, and their total cost. - * We'll use at least some of this info below. (Note we are assuming that - * finalize_plan doesn't touch the initPlans.) - * - * In the case where attach_initplans is false, we are assuming that the - * existing initPlans are siblings that might supply params needed by the - * current plan. + * If no parameters have been assigned anywhere in the tree, we certainly + * don't need to do anything here. */ - initExtParam = initSetParam = NULL; - initplan_cost = 0; - foreach(l, root->init_plans) - { - SubPlan *initsubplan = (SubPlan *) lfirst(l); - Plan *initplan = planner_subplan_get_plan(root, initsubplan); - ListCell *l2; - - initExtParam = bms_add_members(initExtParam, initplan->extParam); - foreach(l2, initsubplan->setParam) - { - initSetParam = bms_add_member(initSetParam, lfirst_int(l2)); - } - initplan_cost += initsubplan->startup_cost + initsubplan->per_call_cost; - } + if (root->glob->nParamExec == 0) + return; /* - * Now determine the set of params that are validly referenceable in this - * query level; to wit, those available from outer query levels plus the - * output parameters of any local initPlans. (We do not include output - * parameters of regular subplans. Those should only appear within the - * testexpr of SubPlan nodes, and are taken care of locally within - * finalize_primnode. Likewise, special parameters that are generated by - * nodes such as ModifyTable are handled within finalize_plan.) + * Scan all query levels above this one to see which parameters are due to + * be available from them, either because lower query levels have + * requested them (via plan_params) or because they will be available from + * initPlans of those levels. */ - valid_params = bms_copy(initSetParam); + outer_params = NULL; for (proot = root->parent_root; proot != NULL; proot = proot->parent_root) { /* Include ordinary Var/PHV/Aggref params */ @@ -2109,7 +2088,7 @@ SS_finalize_plan(PlannerInfo *root, Plan *plan, bool attach_initplans) { PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l); - valid_params = bms_add_member(valid_params, pitem->paramId); + outer_params = bms_add_member(outer_params, pitem->paramId); } /* Include any outputs of outer-level initPlans */ foreach(l, proot->init_plans) @@ -2119,48 +2098,42 @@ SS_finalize_plan(PlannerInfo *root, Plan *plan, bool attach_initplans) foreach(l2, initsubplan->setParam) { - valid_params = bms_add_member(valid_params, lfirst_int(l2)); + outer_params = bms_add_member(outer_params, lfirst_int(l2)); } } /* Include worktable ID, if a recursive query is being planned */ if (proot->wt_param_id >= 0) - valid_params = bms_add_member(valid_params, proot->wt_param_id); + outer_params = bms_add_member(outer_params, proot->wt_param_id); } + root->outer_params = outer_params; +} - /* - * Now recurse through plan tree. - */ - (void) finalize_plan(root, plan, valid_params, NULL); - - bms_free(valid_params); +/* + * SS_attach_initplans - attach initplans to topmost plan node + * + * Attach any initplans created in the current query level to the topmost plan + * node for the query level, and increment that node's cost to account for + * them. (The initPlans could actually go in any node at or above where + * they're referenced, but there seems no reason to put them any lower than + * the topmost node for the query level.) + */ +void +SS_attach_initplans(PlannerInfo *root, Plan *plan) +{ + ListCell *lc; - /* - * Finally, attach any initPlans to the topmost plan node, and add their - * extParams to the topmost node's, too. However, any setParams of the - * initPlans should not be present in the topmost node's extParams, only - * in its allParams. (As of PG 8.1, it's possible that some initPlans - * have extParams that are setParams of other initPlans, so we have to - * take care of this situation explicitly.) - * - * We also add the eval cost of each initPlan to the startup cost of the - * top node. This is a conservative overestimate, since in fact each - * initPlan might be executed later than plan startup, or even not at all. - */ - if (attach_initplans) + plan->initPlan = root->init_plans; + foreach(lc, plan->initPlan) { - plan->initPlan = root->init_plans; - root->init_plans = NIL; /* make sure they're not attached twice */ - - /* allParam must include all these params */ - plan->allParam = bms_add_members(plan->allParam, initExtParam); - plan->allParam = bms_add_members(plan->allParam, initSetParam); - /* extParam must include any child extParam */ - plan->extParam = bms_add_members(plan->extParam, initExtParam); - /* but extParam shouldn't include any setParams */ - plan->extParam = bms_del_members(plan->extParam, initSetParam); - /* ensure extParam is exactly NULL if it's empty */ - if (bms_is_empty(plan->extParam)) - plan->extParam = NULL; + SubPlan *initsubplan = (SubPlan *) lfirst(lc); + Cost initplan_cost; + + /* + * Assume each initPlan gets run once during top plan startup. This + * is a conservative overestimate, since in fact an initPlan might be + * executed later than plan startup, or even not at all. + */ + initplan_cost = initsubplan->startup_cost + initsubplan->per_call_cost; plan->startup_cost += initplan_cost; plan->total_cost += initplan_cost; @@ -2168,16 +2141,35 @@ SS_finalize_plan(PlannerInfo *root, Plan *plan, bool attach_initplans) } /* + * SS_finalize_plan - do final parameter processing for a completed Plan. + * + * This recursively computes the extParam and allParam sets for every Plan + * node in the given plan tree. (Oh, and RangeTblFunction.funcparams too.) + * + * We assume that SS_finalize_plan has already been run on any initplans or + * subplans the plan tree could reference. + */ +void +SS_finalize_plan(PlannerInfo *root, Plan *plan) +{ + /* No setup needed, just recurse through plan tree. */ + (void) finalize_plan(root, plan, root->outer_params, NULL); +} + +/* * Recursive processing of all nodes in the plan tree * - * valid_params is the set of param IDs considered valid to reference in - * this plan node or its children. + * valid_params is the set of param IDs supplied by outer plan levels + * that are valid to reference in this plan node or its children. + * * scan_params is a set of param IDs to force scan plan nodes to reference. * This is for EvalPlanQual support, and is always NULL at the top of the * recursion. * * The return value is the computed allParam set for the given Plan node. * This is just an internal notational convenience. + * + * Do not scribble on caller's values of valid_params or scan_params! */ static Bitmapset * finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params, @@ -2186,7 +2178,10 @@ finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params, finalize_primnode_context context; int locally_added_param; Bitmapset *nestloop_params; + Bitmapset *initExtParam; + Bitmapset *initSetParam; Bitmapset *child_params; + ListCell *l; if (plan == NULL) return NULL; @@ -2197,6 +2192,29 @@ finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params, nestloop_params = NULL; /* there aren't any */ /* + * Examine any initPlans to determine the set of external params they + * reference and the set of output params they supply. (We assume + * SS_finalize_plan was run on them already.) + */ + initExtParam = initSetParam = NULL; + foreach(l, plan->initPlan) + { + SubPlan *initsubplan = (SubPlan *) lfirst(l); + Plan *initplan = planner_subplan_get_plan(root, initsubplan); + ListCell *l2; + + initExtParam = bms_add_members(initExtParam, initplan->extParam); + foreach(l2, initsubplan->setParam) + { + initSetParam = bms_add_member(initSetParam, lfirst_int(l2)); + } + } + + /* Any setParams are validly referenceable in this node and children */ + if (initSetParam) + valid_params = bms_union(valid_params, initSetParam); + + /* * When we call finalize_primnode, context.paramids sets are automatically * merged together. But when recursing to self, we have to do it the hard * way. We want the paramids set to include params in subplans as well as @@ -2274,18 +2292,22 @@ finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params, break; case T_SubqueryScan: + { + SubqueryScan *sscan = (SubqueryScan *) plan; + RelOptInfo *rel; - /* - * In a SubqueryScan, SS_finalize_plan has already been run on the - * subplan by the inner invocation of subquery_planner, so there's - * no need to do it again. Instead, just pull out the subplan's - * extParams list, which represents the params it needs from my - * level and higher levels. - */ - context.paramids = bms_add_members(context.paramids, - ((SubqueryScan *) plan)->subplan->extParam); - /* We need scan_params too, though */ - context.paramids = bms_add_members(context.paramids, scan_params); + /* We must run SS_finalize_plan on the subquery */ + rel = find_base_rel(root, sscan->scan.scanrelid); + Assert(rel->subplan == sscan->subplan); + SS_finalize_plan(rel->subroot, sscan->subplan); + + /* Now we can add its extParams to the parent's params */ + context.paramids = bms_add_members(context.paramids, + sscan->subplan->extParam); + /* We need scan_params too, though */ + context.paramids = bms_add_members(context.paramids, + scan_params); + } break; case T_FunctionScan: @@ -2338,7 +2360,8 @@ finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params, * have to do instead is to find the referenced CTE plan and * incorporate its external paramids, so that the correct * things will happen if the CTE references outer-level - * variables. See test cases for bug #4902. + * variables. See test cases for bug #4902. (We assume + * SS_finalize_plan was run on the CTE plan already.) */ int plan_id = ((CteScan *) plan)->ctePlanId; Plan *cteplan; @@ -2610,30 +2633,35 @@ finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params, locally_added_param); } - /* Now we have all the paramids */ + /* Now we have all the paramids referenced in this node and children */ if (!bms_is_subset(context.paramids, valid_params)) elog(ERROR, "plan should not reference subplan's variable"); /* - * Note: by definition, extParam and allParam should have the same value - * in any plan node that doesn't have child initPlans. We set them equal - * here, and later SS_finalize_plan will update them properly in node(s) - * that it attaches initPlans to. - * + * The plan node's allParam and extParam fields should include all its + * referenced paramids, plus contributions from any child initPlans. + * However, any setParams of the initPlans should not be present in the + * parent node's extParams, only in its allParams. (It's possible that + * some initPlans have extParams that are setParams of other initPlans.) + */ + + /* allParam must include initplans' extParams and setParams */ + plan->allParam = bms_union(context.paramids, initExtParam); + plan->allParam = bms_add_members(plan->allParam, initSetParam); + /* extParam must include any initplan extParams */ + plan->extParam = bms_union(context.paramids, initExtParam); + /* but not any initplan setParams */ + plan->extParam = bms_del_members(plan->extParam, initSetParam); + + /* * For speed at execution time, make sure extParam/allParam are actually * NULL if they are empty sets. */ - if (bms_is_empty(context.paramids)) - { + if (bms_is_empty(plan->extParam)) plan->extParam = NULL; + if (bms_is_empty(plan->allParam)) plan->allParam = NULL; - } - else - { - plan->extParam = context.paramids; - plan->allParam = bms_copy(context.paramids); - } return plan->allParam; } @@ -2686,7 +2714,8 @@ finalize_primnode(Node *node, finalize_primnode_context *context) /* * Add params needed by the subplan to paramids, but excluding those - * we will pass down to it. + * we will pass down to it. (We assume SS_finalize_plan was run on + * the subplan already.) */ subparamids = bms_copy(plan->extParam); foreach(lc, subplan->parParam) @@ -2706,13 +2735,12 @@ finalize_primnode(Node *node, finalize_primnode_context *context) * * The plan is expected to return a scalar value of the given type/collation. * We build an EXPR_SUBLINK SubPlan node and put it into the initplan - * list for the current query level. A Param that represents the initplan's + * list for the outer query level. A Param that represents the initplan's * output is returned. - * - * We assume the plan hasn't been put through SS_finalize_plan. */ Param * -SS_make_initplan_from_plan(PlannerInfo *root, Plan *plan, +SS_make_initplan_from_plan(PlannerInfo *root, + PlannerInfo *subroot, Plan *plan, Oid resulttype, int32 resulttypmod, Oid resultcollation) { @@ -2720,24 +2748,10 @@ SS_make_initplan_from_plan(PlannerInfo *root, Plan *plan, Param *prm; /* - * We must run SS_finalize_plan(), since that's normally done before a - * subplan gets put into the initplan list. Tell it not to attach any - * pre-existing initplans to this one, since they are siblings not - * children of this initplan. (This is something else that could perhaps - * be cleaner if we did extParam/allParam processing in setrefs.c instead - * of here? See notes for materialize_finished_plan.) - */ - - /* - * Build extParam/allParam sets for plan nodes. - */ - SS_finalize_plan(root, plan, false); - - /* * Add the subplan and its PlannerInfo to the global lists. */ root->glob->subplans = lappend(root->glob->subplans, plan); - root->glob->subroots = lappend(root->glob->subroots, root); + root->glob->subroots = lappend(root->glob->subroots, subroot); /* * Create a SubPlan node and add it to the outer list of InitPlans. Note @@ -2757,7 +2771,7 @@ SS_make_initplan_from_plan(PlannerInfo *root, Plan *plan, * parParam and args lists remain empty. */ - cost_subplan(root, node, plan); + cost_subplan(subroot, node, plan); /* * Make a Param that will be the subplan's output. |