* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.131 2008/07/10 01:17:29 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.132 2008/07/10 02:14:03 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* SS_finalize_plan - do final sublink processing for a completed Plan.
*
* This recursively computes the extParam and allParam sets for every Plan
- * node in the given plan tree. It also attaches any generated InitPlans
- * to the top plan node.
+ * 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.)
*/
void
-SS_finalize_plan(PlannerInfo *root, Plan *plan)
+SS_finalize_plan(PlannerInfo *root, Plan *plan, bool attach_initplans)
{
Bitmapset *valid_params,
*initExtParam,
ListCell *l;
/*
- * First, scan the param list to discover the sets of params that are
- * available from outer query levels and my own query level. We do this
- * once to save time in the per-plan recursion steps. (This calculation
- * is overly generous: it can include a lot of params that actually
- * shouldn't be referenced here. However, valid_params is just used as
- * a debugging crosscheck, so it's not worth trying to be exact.)
+ * 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.
+ */
+ 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 += get_initplan_cost(root, initsubplan);
+ }
+
+ /*
+ * 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 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.)
+ *
+ * Note: this is a bit overly generous since some parameters of upper
+ * query levels might belong to query subtrees that don't include this
+ * query. However, valid_params is only a debugging crosscheck, so it
+ * doesn't seem worth expending lots of cycles to try to be exact.
*/
- valid_params = NULL;
+ valid_params = bms_copy(initSetParam);
paramid = 0;
foreach(l, root->glob->paramlist)
{
/* valid outer-level parameter */
valid_params = bms_add_member(valid_params, paramid);
}
- else if (pitem->abslevel == root->query_level &&
- IsA(pitem->item, Param))
- {
- /* valid local parameter (i.e., a setParam of my child) */
- valid_params = bms_add_member(valid_params, paramid);
- }
paramid++;
}
* top node. This is a conservative overestimate, since in fact each
* initPlan might be executed later than plan startup, or even not at all.
*/
- plan->initPlan = root->init_plans;
- root->init_plans = NIL; /* make sure they're not attached twice */
-
- initExtParam = initSetParam = NULL;
- initplan_cost = 0;
- foreach(l, plan->initPlan)
+ if (attach_initplans)
{
- 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 += get_initplan_cost(root, initsubplan);
+ 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;
+
+ plan->startup_cost += initplan_cost;
+ plan->total_cost += initplan_cost;
}
- /* 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;
-
- plan->startup_cost += initplan_cost;
- plan->total_cost += initplan_cost;
}
/*
SS_make_initplan_from_plan(PlannerInfo *root, Plan *plan,
Oid resulttype, int32 resulttypmod)
{
- List *saved_init_plans;
SubPlan *node;
Param *prm;
/*
* We must run SS_finalize_plan(), since that's normally done before a
- * subplan gets put into the initplan list. However it will try to attach
- * any pre-existing initplans to this one, which we don't want (they are
- * siblings not children of this initplan). So, a quick kluge to hide
- * them. (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.)
+ * 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.)
*/
- saved_init_plans = root->init_plans;
- root->init_plans = NIL;
/*
* Build extParam/allParam sets for plan nodes.
*/
- SS_finalize_plan(root, plan);
-
- /* Restore outer initplan list */
- root->init_plans = saved_init_plans;
+ SS_finalize_plan(root, plan, false);
/*
* Add the subplan and its rtable to the global lists.
/*
* Create a SubPlan node and add it to the outer list of InitPlans.
+ * Note it has to appear after any other InitPlans it might depend on
+ * (see comments in ExecReScan).
*/
node = makeNode(SubPlan);
node->subLinkType = EXPR_SUBLINK;
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