diff options
Diffstat (limited to 'src/backend/optimizer/plan/subselect.c')
| -rw-r--r-- | src/backend/optimizer/plan/subselect.c | 396 |
1 files changed, 26 insertions, 370 deletions
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index cb1ea86afb2..64272dd6500 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -1,7 +1,10 @@ /*------------------------------------------------------------------------- * * subselect.c - * Planning routines for subselects and parameters. + * Planning routines for subselects. + * + * This module deals with SubLinks and CTEs, but not subquery RTEs (i.e., + * not sub-SELECT-in-FROM cases). * * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California @@ -22,6 +25,7 @@ #include "nodes/nodeFuncs.h" #include "optimizer/clauses.h" #include "optimizer/cost.h" +#include "optimizer/paramassign.h" #include "optimizer/pathnode.h" #include "optimizer/planmain.h" #include "optimizer/planner.h" @@ -87,355 +91,6 @@ static bool finalize_agg_primnode(Node *node, finalize_primnode_context *context /* - * Select a PARAM_EXEC number to identify the given Var as a parameter for - * the current subquery, or for a nestloop's inner scan. - * If the Var already has a param in the current context, return that one. - */ -static int -assign_param_for_var(PlannerInfo *root, Var *var) -{ - ListCell *ppl; - PlannerParamItem *pitem; - Index levelsup; - - /* Find the query level the Var belongs to */ - for (levelsup = var->varlevelsup; levelsup > 0; levelsup--) - root = root->parent_root; - - /* If there's already a matching PlannerParamItem there, just use it */ - foreach(ppl, root->plan_params) - { - pitem = (PlannerParamItem *) lfirst(ppl); - if (IsA(pitem->item, Var)) - { - Var *pvar = (Var *) pitem->item; - - /* - * This comparison must match _equalVar(), except for ignoring - * varlevelsup. Note that _equalVar() ignores the location. - */ - if (pvar->varno == var->varno && - pvar->varattno == var->varattno && - pvar->vartype == var->vartype && - pvar->vartypmod == var->vartypmod && - pvar->varcollid == var->varcollid && - pvar->varnoold == var->varnoold && - pvar->varoattno == var->varoattno) - return pitem->paramId; - } - } - - /* Nope, so make a new one */ - var = copyObject(var); - var->varlevelsup = 0; - - pitem = makeNode(PlannerParamItem); - pitem->item = (Node *) var; - pitem->paramId = list_length(root->glob->paramExecTypes); - root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes, - var->vartype); - - root->plan_params = lappend(root->plan_params, pitem); - - return pitem->paramId; -} - -/* - * Generate a Param node to replace the given Var, - * which is expected to have varlevelsup > 0 (ie, it is not local). - */ -static Param * -replace_outer_var(PlannerInfo *root, Var *var) -{ - Param *retval; - int i; - - Assert(var->varlevelsup > 0 && var->varlevelsup < root->query_level); - - /* Find the Var in the appropriate plan_params, or add it if not present */ - i = assign_param_for_var(root, var); - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = i; - retval->paramtype = var->vartype; - retval->paramtypmod = var->vartypmod; - retval->paramcollid = var->varcollid; - retval->location = var->location; - - return retval; -} - -/* - * Generate a Param node to replace the given Var, which will be supplied - * from an upper NestLoop join node. - * - * This is effectively the same as replace_outer_var, except that we expect - * the Var to be local to the current query level. - */ -Param * -assign_nestloop_param_var(PlannerInfo *root, Var *var) -{ - Param *retval; - int i; - - Assert(var->varlevelsup == 0); - - i = assign_param_for_var(root, var); - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = i; - retval->paramtype = var->vartype; - retval->paramtypmod = var->vartypmod; - retval->paramcollid = var->varcollid; - retval->location = var->location; - - return retval; -} - -/* - * Select a PARAM_EXEC number to identify the given PlaceHolderVar as a - * parameter for the current subquery, or for a nestloop's inner scan. - * If the PHV already has a param in the current context, return that one. - * - * This is just like assign_param_for_var, except for PlaceHolderVars. - */ -static int -assign_param_for_placeholdervar(PlannerInfo *root, PlaceHolderVar *phv) -{ - ListCell *ppl; - PlannerParamItem *pitem; - Index levelsup; - - /* Find the query level the PHV belongs to */ - for (levelsup = phv->phlevelsup; levelsup > 0; levelsup--) - root = root->parent_root; - - /* If there's already a matching PlannerParamItem there, just use it */ - foreach(ppl, root->plan_params) - { - pitem = (PlannerParamItem *) lfirst(ppl); - if (IsA(pitem->item, PlaceHolderVar)) - { - PlaceHolderVar *pphv = (PlaceHolderVar *) pitem->item; - - /* We assume comparing the PHIDs is sufficient */ - if (pphv->phid == phv->phid) - return pitem->paramId; - } - } - - /* Nope, so make a new one */ - phv = copyObject(phv); - if (phv->phlevelsup != 0) - { - IncrementVarSublevelsUp((Node *) phv, -((int) phv->phlevelsup), 0); - Assert(phv->phlevelsup == 0); - } - - pitem = makeNode(PlannerParamItem); - pitem->item = (Node *) phv; - pitem->paramId = list_length(root->glob->paramExecTypes); - root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes, - exprType((Node *) phv->phexpr)); - - root->plan_params = lappend(root->plan_params, pitem); - - return pitem->paramId; -} - -/* - * Generate a Param node to replace the given PlaceHolderVar, - * which is expected to have phlevelsup > 0 (ie, it is not local). - * - * This is just like replace_outer_var, except for PlaceHolderVars. - */ -static Param * -replace_outer_placeholdervar(PlannerInfo *root, PlaceHolderVar *phv) -{ - Param *retval; - int i; - - Assert(phv->phlevelsup > 0 && phv->phlevelsup < root->query_level); - - /* Find the PHV in the appropriate plan_params, or add it if not present */ - i = assign_param_for_placeholdervar(root, phv); - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = i; - retval->paramtype = exprType((Node *) phv->phexpr); - retval->paramtypmod = exprTypmod((Node *) phv->phexpr); - retval->paramcollid = exprCollation((Node *) phv->phexpr); - retval->location = -1; - - return retval; -} - -/* - * Generate a Param node to replace the given PlaceHolderVar, which will be - * supplied from an upper NestLoop join node. - * - * This is just like assign_nestloop_param_var, except for PlaceHolderVars. - */ -Param * -assign_nestloop_param_placeholdervar(PlannerInfo *root, PlaceHolderVar *phv) -{ - Param *retval; - int i; - - Assert(phv->phlevelsup == 0); - - i = assign_param_for_placeholdervar(root, phv); - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = i; - retval->paramtype = exprType((Node *) phv->phexpr); - retval->paramtypmod = exprTypmod((Node *) phv->phexpr); - retval->paramcollid = exprCollation((Node *) phv->phexpr); - retval->location = -1; - - return retval; -} - -/* - * Generate a Param node to replace the given Aggref - * which is expected to have agglevelsup > 0 (ie, it is not local). - */ -static Param * -replace_outer_agg(PlannerInfo *root, Aggref *agg) -{ - Param *retval; - PlannerParamItem *pitem; - Index levelsup; - - Assert(agg->agglevelsup > 0 && agg->agglevelsup < root->query_level); - - /* Find the query level the Aggref belongs to */ - for (levelsup = agg->agglevelsup; levelsup > 0; levelsup--) - root = root->parent_root; - - /* - * It does not seem worthwhile to try to match duplicate outer aggs. Just - * make a new slot every time. - */ - agg = copyObject(agg); - IncrementVarSublevelsUp((Node *) agg, -((int) agg->agglevelsup), 0); - Assert(agg->agglevelsup == 0); - - pitem = makeNode(PlannerParamItem); - pitem->item = (Node *) agg; - pitem->paramId = list_length(root->glob->paramExecTypes); - root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes, - agg->aggtype); - - root->plan_params = lappend(root->plan_params, pitem); - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = pitem->paramId; - retval->paramtype = agg->aggtype; - retval->paramtypmod = -1; - retval->paramcollid = agg->aggcollid; - retval->location = agg->location; - - return retval; -} - -/* - * Generate a Param node to replace the given GroupingFunc expression which is - * expected to have agglevelsup > 0 (ie, it is not local). - */ -static Param * -replace_outer_grouping(PlannerInfo *root, GroupingFunc *grp) -{ - Param *retval; - PlannerParamItem *pitem; - Index levelsup; - Oid ptype; - - Assert(grp->agglevelsup > 0 && grp->agglevelsup < root->query_level); - - /* Find the query level the GroupingFunc belongs to */ - for (levelsup = grp->agglevelsup; levelsup > 0; levelsup--) - root = root->parent_root; - - /* - * It does not seem worthwhile to try to match duplicate outer aggs. Just - * make a new slot every time. - */ - grp = copyObject(grp); - IncrementVarSublevelsUp((Node *) grp, -((int) grp->agglevelsup), 0); - Assert(grp->agglevelsup == 0); - ptype = exprType((Node *) grp); - - pitem = makeNode(PlannerParamItem); - pitem->item = (Node *) grp; - pitem->paramId = list_length(root->glob->paramExecTypes); - root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes, - ptype); - - root->plan_params = lappend(root->plan_params, pitem); - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = pitem->paramId; - retval->paramtype = ptype; - retval->paramtypmod = -1; - retval->paramcollid = InvalidOid; - retval->location = grp->location; - - return retval; -} - -/* - * Generate a new Param node that will not conflict with any other. - * - * This is used to create Params representing subplan outputs. - * We don't need to build a PlannerParamItem for such a Param, but we do - * need to make sure we record the type in paramExecTypes (otherwise, - * there won't be a slot allocated for it). - */ -static Param * -generate_new_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod, - Oid paramcollation) -{ - Param *retval; - - retval = makeNode(Param); - retval->paramkind = PARAM_EXEC; - retval->paramid = list_length(root->glob->paramExecTypes); - root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes, - paramtype); - retval->paramtype = paramtype; - retval->paramtypmod = paramtypmod; - retval->paramcollid = paramcollation; - retval->location = -1; - - return retval; -} - -/* - * Assign a (nonnegative) PARAM_EXEC ID for a special parameter (one that - * is not actually used to carry a value at runtime). Such parameters are - * used for special runtime signaling purposes, such as connecting a - * recursive union node to its worktable scan node or forcing plan - * re-evaluation within the EvalPlanQual mechanism. No actual Param node - * exists with this ID, however. - */ -int -SS_assign_special_param(PlannerInfo *root) -{ - int paramId = list_length(root->glob->paramExecTypes); - - root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes, - InvalidOid); - return paramId; -} - -/* * Get the datatype/typmod/collation of the first column of the plan's output. * * This information is stored for ARRAY_SUBLINK execution and for @@ -716,7 +371,7 @@ build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot, Param *prm; Assert(testexpr == NULL); - prm = generate_new_param(root, BOOLOID, -1, InvalidOid); + prm = generate_new_exec_param(root, BOOLOID, -1, InvalidOid); splan->setParam = list_make1_int(prm->paramid); isInitPlan = true; result = (Node *) prm; @@ -728,10 +383,10 @@ build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot, Assert(!te->resjunk); Assert(testexpr == NULL); - prm = generate_new_param(root, - exprType((Node *) te->expr), - exprTypmod((Node *) te->expr), - exprCollation((Node *) te->expr)); + prm = generate_new_exec_param(root, + exprType((Node *) te->expr), + exprTypmod((Node *) te->expr), + exprCollation((Node *) te->expr)); splan->setParam = list_make1_int(prm->paramid); isInitPlan = true; result = (Node *) prm; @@ -748,10 +403,10 @@ build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot, if (!OidIsValid(arraytype)) elog(ERROR, "could not find array type for datatype %s", format_type_be(exprType((Node *) te->expr))); - prm = generate_new_param(root, - arraytype, - exprTypmod((Node *) te->expr), - exprCollation((Node *) te->expr)); + prm = generate_new_exec_param(root, + arraytype, + exprTypmod((Node *) te->expr), + exprCollation((Node *) te->expr)); splan->setParam = list_make1_int(prm->paramid); isInitPlan = true; result = (Node *) prm; @@ -930,10 +585,10 @@ generate_subquery_params(PlannerInfo *root, List *tlist, List **paramIds) if (tent->resjunk) continue; - param = generate_new_param(root, - exprType((Node *) tent->expr), - exprTypmod((Node *) tent->expr), - exprCollation((Node *) tent->expr)); + param = generate_new_exec_param(root, + exprType((Node *) tent->expr), + exprTypmod((Node *) tent->expr), + exprCollation((Node *) tent->expr)); result = lappend(result, param); ids = lappend_int(ids, param->paramid); } @@ -1257,7 +912,7 @@ SS_process_ctes(PlannerInfo *root) * ParamExecData slot for this param ID for communication among * multiple CteScan nodes that might be scanning this CTE.) */ - paramid = SS_assign_special_param(root); + paramid = assign_special_exec_param(root); splan->setParam = list_make1_int(paramid); /* @@ -1863,10 +1518,10 @@ convert_EXISTS_to_ANY(PlannerInfo *root, Query *subselect, Param *param; cc = lnext(cc); - param = generate_new_param(root, - exprType(rightarg), - exprTypmod(rightarg), - exprCollation(rightarg)); + param = generate_new_exec_param(root, + exprType(rightarg), + exprTypmod(rightarg), + exprCollation(rightarg)); tlist = lappend(tlist, makeTargetEntry((Expr *) rightarg, resno++, @@ -2917,7 +2572,7 @@ finalize_primnode(Node *node, finalize_primnode_context *context) * parameter change signaling since we always re-evaluate the subplan. * Note that this wouldn't work too well if there might be uses of the * same param IDs elsewhere in the plan, but that can't happen because - * generate_new_param never tries to merge params. + * generate_new_exec_param never tries to merge params. */ foreach(lc, subplan->paramIds) { @@ -2983,7 +2638,8 @@ SS_make_initplan_output_param(PlannerInfo *root, Oid resulttype, int32 resulttypmod, Oid resultcollation) { - return generate_new_param(root, resulttype, resulttypmod, resultcollation); + return generate_new_exec_param(root, resulttype, + resulttypmod, resultcollation); } /* |