Re: 9.2rc1 produces incorrect results - Mailing list pgsql-hackers
| From | Tom Lane |
|---|---|
| Subject | Re: 9.2rc1 produces incorrect results |
| Date | |
| Msg-id | 3521.1346818143@sss.pgh.pa.us Whole thread Raw |
| In response to | Re: 9.2rc1 produces incorrect results (Tom Lane <tgl@sss.pgh.pa.us>) |
| Responses |
Re: 9.2rc1 produces incorrect results
Re: 9.2rc1 produces incorrect results Re: 9.2rc1 produces incorrect results |
| List | pgsql-hackers |
I wrote:
> I think probably the best fix is to rejigger things so that Params
> assigned by different executions of SS_replace_correlation_vars and
> createplan.c can't share PARAM_EXEC numbers. This will result in
> rather larger ecxt_param_exec_vals arrays at runtime, but the array
> entries aren't very large, so I don't think it'll matter.
Attached is a draft patch against HEAD for this. I think it makes the
planner's handling of outer-level Params far less squishy than it's ever
been, but it is rather a large change. Not sure whether to risk pushing
it into 9.2 right now, or wait till after we cut 9.2.0 ... thoughts?
regards, tom lane
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 1f2bb6cc72f1242f14d55eee7cdc8e0e0d0775a9..02a0f62a53a4e3d06a3ad48d523e959d5d6b2ab7 100644
*** a/src/backend/nodes/outfuncs.c
--- b/src/backend/nodes/outfuncs.c
*************** _outPlannerGlobal(StringInfo str, const
*** 1666,1672 ****
WRITE_NODE_TYPE("PLANNERGLOBAL");
/* NB: this isn't a complete set of fields */
- WRITE_NODE_FIELD(paramlist);
WRITE_NODE_FIELD(subplans);
WRITE_BITMAPSET_FIELD(rewindPlanIDs);
WRITE_NODE_FIELD(finalrtable);
--- 1666,1671 ----
*************** _outPlannerGlobal(StringInfo str, const
*** 1674,1679 ****
--- 1673,1679 ----
WRITE_NODE_FIELD(resultRelations);
WRITE_NODE_FIELD(relationOids);
WRITE_NODE_FIELD(invalItems);
+ WRITE_INT_FIELD(nParamExec);
WRITE_UINT_FIELD(lastPHId);
WRITE_UINT_FIELD(lastRowMarkId);
WRITE_BOOL_FIELD(transientPlan);
*************** _outPlannerInfo(StringInfo str, const Pl
*** 1688,1693 ****
--- 1688,1694 ----
WRITE_NODE_FIELD(parse);
WRITE_NODE_FIELD(glob);
WRITE_UINT_FIELD(query_level);
+ WRITE_NODE_FIELD(plan_params);
WRITE_BITMAPSET_FIELD(all_baserels);
WRITE_NODE_FIELD(join_rel_list);
WRITE_INT_FIELD(join_cur_level);
*************** _outRelOptInfo(StringInfo str, const Rel
*** 1754,1759 ****
--- 1755,1761 ----
WRITE_FLOAT_FIELD(allvisfrac, "%.6f");
WRITE_NODE_FIELD(subplan);
WRITE_NODE_FIELD(subroot);
+ WRITE_NODE_FIELD(subplan_params);
/* we don't try to print fdwroutine or fdw_private */
WRITE_NODE_FIELD(baserestrictinfo);
WRITE_NODE_FIELD(joininfo);
*************** _outPlannerParamItem(StringInfo str, con
*** 1950,1956 ****
WRITE_NODE_TYPE("PLANNERPARAMITEM");
WRITE_NODE_FIELD(item);
! WRITE_UINT_FIELD(abslevel);
}
/*****************************************************************************
--- 1952,1958 ----
WRITE_NODE_TYPE("PLANNERPARAMITEM");
WRITE_NODE_FIELD(item);
! WRITE_INT_FIELD(paramId);
}
/*****************************************************************************
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 69a1b93b33746370457bff2daf4d4ece66535803..458dae0489c029bd743c75c82f8e5102067e89bf 100644
*** a/src/backend/optimizer/path/allpaths.c
--- b/src/backend/optimizer/path/allpaths.c
*************** set_subquery_pathlist(PlannerInfo *root,
*** 1145,1150 ****
--- 1145,1153 ----
else
tuple_fraction = root->tuple_fraction;
+ /* plan_params should not be in use in current query level */
+ Assert(root->plan_params == NIL);
+
/* Generate the plan for the subquery */
rel->subplan = subquery_planner(root->glob, subquery,
root,
*************** set_subquery_pathlist(PlannerInfo *root,
*** 1152,1157 ****
--- 1155,1164 ----
&subroot);
rel->subroot = subroot;
+ /* Isolate the params needed by this specific subplan */
+ rel->subplan_params = root->plan_params;
+ root->plan_params = NIL;
+
/*
* It's possible that constraint exclusion proved the subquery empty. If
* so, it's convenient to turn it back into a dummy path so that we will
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 5d3b293b88a3ee030adae2260520eda69caad4b7..030f420c90eb37946ee333250de54af61d9b82d7 100644
*** a/src/backend/optimizer/plan/createplan.c
--- b/src/backend/optimizer/plan/createplan.c
*************** static HashJoin *create_hashjoin_plan(Pl
*** 84,90 ****
Plan *outer_plan, Plan *inner_plan);
static Node *replace_nestloop_params(PlannerInfo *root, Node *expr);
static Node *replace_nestloop_params_mutator(Node *node, PlannerInfo *root);
! static void identify_nestloop_extparams(PlannerInfo *root, Plan *subplan);
static List *fix_indexqual_references(PlannerInfo *root, IndexPath *index_path);
static List *fix_indexorderby_references(PlannerInfo *root, IndexPath *index_path);
static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index, int indexcol);
--- 84,91 ----
Plan *outer_plan, Plan *inner_plan);
static Node *replace_nestloop_params(PlannerInfo *root, Node *expr);
static Node *replace_nestloop_params_mutator(Node *node, PlannerInfo *root);
! static void process_subquery_nestloop_params(PlannerInfo *root,
! List *subplan_params);
static List *fix_indexqual_references(PlannerInfo *root, IndexPath *index_path);
static List *fix_indexorderby_references(PlannerInfo *root, IndexPath *index_path);
static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index, int indexcol);
*************** create_plan(PlannerInfo *root, Path *bes
*** 188,193 ****
--- 189,197 ----
{
Plan *plan;
+ /* plan_params should not be in use in current query level */
+ Assert(root->plan_params == NIL);
+
/* Initialize this module's private workspace in PlannerInfo */
root->curOuterRels = NULL;
root->curOuterParams = NIL;
*************** create_plan(PlannerInfo *root, Path *bes
*** 199,204 ****
--- 203,214 ----
if (root->curOuterParams != NIL)
elog(ERROR, "failed to assign all NestLoopParams to plan nodes");
+ /*
+ * Reset plan_params to ensure param IDs used for nestloop params are not
+ * re-used later
+ */
+ root->plan_params = NIL;
+
return plan;
}
*************** create_subqueryscan_plan(PlannerInfo *ro
*** 1662,1668 ****
{
scan_clauses = (List *)
replace_nestloop_params(root, (Node *) scan_clauses);
! identify_nestloop_extparams(root, best_path->parent->subplan);
}
scan_plan = make_subqueryscan(tlist,
--- 1672,1679 ----
{
scan_clauses = (List *)
replace_nestloop_params(root, (Node *) scan_clauses);
! process_subquery_nestloop_params(root,
! best_path->parent->subplan_params);
}
scan_plan = make_subqueryscan(tlist,
*************** replace_nestloop_params_mutator(Node *no
*** 2620,2649 ****
}
/*
! * identify_nestloop_extparams
! * Identify extParams of a parameterized subquery that need to be fed
* from an outer nestloop.
*
* The subplan's references to the outer variables are already represented
* as PARAM_EXEC Params, so we need not modify the subplan here. What we
* do need to do is add entries to root->curOuterParams to signal the parent
* nestloop plan node that it must provide these values.
*/
static void
! identify_nestloop_extparams(PlannerInfo *root, Plan *subplan)
{
! Bitmapset *tmpset;
! int paramid;
! /* Examine each extParam of the subquery's plan */
! tmpset = bms_copy(subplan->extParam);
! while ((paramid = bms_first_member(tmpset)) >= 0)
{
! PlannerParamItem *pitem = list_nth(root->glob->paramlist, paramid);
!
! /* Ignore anything coming from an upper query level */
! if (pitem->abslevel != root->query_level)
! continue;
if (IsA(pitem->item, Var))
{
--- 2631,2656 ----
}
/*
! * process_subquery_nestloop_params
! * Handle params of a parameterized subquery that need to be fed
* from an outer nestloop.
*
+ * Currently, that would be *all* params that a subquery in FROM has demanded
+ * from the current query level, since they must be LATERAL references.
+ *
* The subplan's references to the outer variables are already represented
* as PARAM_EXEC Params, so we need not modify the subplan here. What we
* do need to do is add entries to root->curOuterParams to signal the parent
* nestloop plan node that it must provide these values.
*/
static void
! process_subquery_nestloop_params(PlannerInfo *root, List *subplan_params)
{
! ListCell *ppl;
! foreach(ppl, subplan_params)
{
! PlannerParamItem *pitem = (PlannerParamItem *) lfirst(ppl);
if (IsA(pitem->item, Var))
{
*************** identify_nestloop_extparams(PlannerInfo
*** 2651,2664 ****
NestLoopParam *nlp;
ListCell *lc;
! /* If not from a nestloop outer rel, nothing to do */
if (!bms_is_member(var->varno, root->curOuterRels))
! continue;
/* Is this param already listed in root->curOuterParams? */
foreach(lc, root->curOuterParams)
{
nlp = (NestLoopParam *) lfirst(lc);
! if (nlp->paramno == paramid)
{
Assert(equal(var, nlp->paramval));
/* Present, so nothing to do */
--- 2658,2671 ----
NestLoopParam *nlp;
ListCell *lc;
! /* If not from a nestloop outer rel, complain */
if (!bms_is_member(var->varno, root->curOuterRels))
! elog(ERROR, "non-LATERAL parameter required by subquery");
/* Is this param already listed in root->curOuterParams? */
foreach(lc, root->curOuterParams)
{
nlp = (NestLoopParam *) lfirst(lc);
! if (nlp->paramno == pitem->paramId)
{
Assert(equal(var, nlp->paramval));
/* Present, so nothing to do */
*************** identify_nestloop_extparams(PlannerInfo
*** 2669,2675 ****
{
/* No, so add it */
nlp = makeNode(NestLoopParam);
! nlp->paramno = paramid;
nlp->paramval = copyObject(var);
root->curOuterParams = lappend(root->curOuterParams, nlp);
}
--- 2676,2682 ----
{
/* No, so add it */
nlp = makeNode(NestLoopParam);
! nlp->paramno = pitem->paramId;
nlp->paramval = copyObject(var);
root->curOuterParams = lappend(root->curOuterParams, nlp);
}
*************** identify_nestloop_extparams(PlannerInfo
*** 2680,2701 ****
NestLoopParam *nlp;
ListCell *lc;
! /*
! * If not from a nestloop outer rel, nothing to do. We use
! * bms_overlap as a cheap/quick test to see if the PHV might be
! * evaluated in the outer rels, and then grab its PlaceHolderInfo
! * to tell for sure.
! */
! if (!bms_overlap(phv->phrels, root->curOuterRels))
! continue;
if (!bms_is_subset(find_placeholder_info(root, phv, false)->ph_eval_at,
root->curOuterRels))
! continue;
/* Is this param already listed in root->curOuterParams? */
foreach(lc, root->curOuterParams)
{
nlp = (NestLoopParam *) lfirst(lc);
! if (nlp->paramno == paramid)
{
Assert(equal(phv, nlp->paramval));
/* Present, so nothing to do */
--- 2687,2701 ----
NestLoopParam *nlp;
ListCell *lc;
! /* If not from a nestloop outer rel, complain */
if (!bms_is_subset(find_placeholder_info(root, phv, false)->ph_eval_at,
root->curOuterRels))
! elog(ERROR, "non-LATERAL parameter required by subquery");
/* Is this param already listed in root->curOuterParams? */
foreach(lc, root->curOuterParams)
{
nlp = (NestLoopParam *) lfirst(lc);
! if (nlp->paramno == pitem->paramId)
{
Assert(equal(phv, nlp->paramval));
/* Present, so nothing to do */
*************** identify_nestloop_extparams(PlannerInfo
*** 2706,2718 ****
{
/* No, so add it */
nlp = makeNode(NestLoopParam);
! nlp->paramno = paramid;
nlp->paramval = copyObject(phv);
root->curOuterParams = lappend(root->curOuterParams, nlp);
}
}
}
- bms_free(tmpset);
}
/*
--- 2706,2719 ----
{
/* No, so add it */
nlp = makeNode(NestLoopParam);
! nlp->paramno = pitem->paramId;
nlp->paramval = copyObject(phv);
root->curOuterParams = lappend(root->curOuterParams, nlp);
}
}
+ else
+ elog(ERROR, "unexpected type of subquery parameter");
}
}
/*
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 4284eed47b929f7c9cca8c75bcde3487fc13c65f..385e64647ea0dea00c15889064421a01ad2dab79 100644
*** a/src/backend/optimizer/plan/planner.c
--- b/src/backend/optimizer/plan/planner.c
*************** standard_planner(Query *parse, int curso
*** 155,161 ****
glob = makeNode(PlannerGlobal);
glob->boundParams = boundParams;
- glob->paramlist = NIL;
glob->subplans = NIL;
glob->subroots = NIL;
glob->rewindPlanIDs = NULL;
--- 155,160 ----
*************** standard_planner(Query *parse, int curso
*** 164,169 ****
--- 163,169 ----
glob->resultRelations = NIL;
glob->relationOids = NIL;
glob->invalItems = NIL;
+ glob->nParamExec = 0;
glob->lastPHId = 0;
glob->lastRowMarkId = 0;
glob->transientPlan = false;
*************** standard_planner(Query *parse, int curso
*** 243,249 ****
result->rowMarks = glob->finalrowmarks;
result->relationOids = glob->relationOids;
result->invalItems = glob->invalItems;
! result->nParamExec = list_length(glob->paramlist);
return result;
}
--- 243,249 ----
result->rowMarks = glob->finalrowmarks;
result->relationOids = glob->relationOids;
result->invalItems = glob->invalItems;
! result->nParamExec = glob->nParamExec;
return result;
}
*************** subquery_planner(PlannerGlobal *glob, Qu
*** 295,300 ****
--- 295,301 ----
root->glob = glob;
root->query_level = parent_root ? parent_root->query_level + 1 : 1;
root->parent_root = parent_root;
+ root->plan_params = NIL;
root->planner_cxt = CurrentMemoryContext;
root->init_plans = NIL;
root->cte_plan_ids = NIL;
*************** subquery_planner(PlannerGlobal *glob, Qu
*** 586,592 ****
* and attach the initPlans to the top plan node.
*/
if (list_length(glob->subplans) != num_old_subplans ||
! root->glob->paramlist != NIL)
SS_finalize_plan(root, plan, true);
/* Return internal info if caller wants it */
--- 587,593 ----
* and attach the initPlans to the top plan node.
*/
if (list_length(glob->subplans) != num_old_subplans ||
! root->glob->nParamExec > 0)
SS_finalize_plan(root, plan, true);
/* Return internal info if caller wants it */
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 4c2e82128181b8bbbfb4c527b0db8eed1714b6df..305888214a57d699a348a5db6acf28a6c6befe46 100644
*** a/src/backend/optimizer/plan/subselect.c
--- b/src/backend/optimizer/plan/subselect.c
*************** typedef struct finalize_primnode_context
*** 54,59 ****
--- 54,60 ----
static Node *build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot,
+ List *plan_params,
SubLinkType subLinkType, Node *testexpr,
bool adjust_testexpr, bool unknownEqFalse);
static List *generate_subquery_params(PlannerInfo *root, List *tlist,
*************** static bool finalize_primnode(Node *node
*** 82,116 ****
/*
! * Select a PARAM_EXEC number to identify the given Var.
! * If the Var already has a param slot, return that one.
*/
static int
assign_param_for_var(PlannerInfo *root, Var *var)
{
ListCell *ppl;
PlannerParamItem *pitem;
! Index abslevel;
! int i;
! abslevel = root->query_level - var->varlevelsup;
! /* If there's already a paramlist entry for this same Var, just use it */
! i = 0;
! foreach(ppl, root->glob->paramlist)
{
pitem = (PlannerParamItem *) lfirst(ppl);
! if (pitem->abslevel == abslevel && IsA(pitem->item, Var))
{
Var *pvar = (Var *) pitem->item;
if (pvar->varno == var->varno &&
pvar->varattno == var->varattno &&
pvar->vartype == var->vartype &&
! pvar->vartypmod == var->vartypmod)
! return i;
}
- i++;
}
/* Nope, so make a new one */
--- 83,124 ----
/*
! * 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 */
*************** assign_param_for_var(PlannerInfo *root,
*** 119,130 ****
pitem = makeNode(PlannerParamItem);
pitem->item = (Node *) var;
! pitem->abslevel = abslevel;
! root->glob->paramlist = lappend(root->glob->paramlist, pitem);
! /* i is already the correct list index for the new item */
! return i;
}
/*
--- 127,137 ----
pitem = makeNode(PlannerParamItem);
pitem->item = (Node *) var;
! pitem->paramId = root->glob->nParamExec++;
! root->plan_params = lappend(root->plan_params, pitem);
! return pitem->paramId;
}
/*
*************** replace_outer_var(PlannerInfo *root, Var
*** 139,154 ****
Assert(var->varlevelsup > 0 && var->varlevelsup < root->query_level);
! /*
! * Find the Var in root->glob->paramlist, or add it if not present.
! *
! * NOTE: in sufficiently complex querytrees, it is possible for the same
! * varno/abslevel to refer to different RTEs in different parts of the
! * parsetree, so that different fields might end up sharing the same Param
! * number. As long as we check the vartype/typmod as well, I believe that
! * this sort of aliasing will cause no trouble. The correct field should
! * get stored into the Param slot at execution in each part of the tree.
! */
i = assign_param_for_var(root, var);
retval = makeNode(Param);
--- 146,152 ----
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);
*************** replace_outer_var(PlannerInfo *root, Var
*** 157,163 ****
retval->paramtype = var->vartype;
retval->paramtypmod = var->vartypmod;
retval->paramcollid = var->varcollid;
! retval->location = -1;
return retval;
}
--- 155,161 ----
retval->paramtype = var->vartype;
retval->paramtypmod = var->vartypmod;
retval->paramcollid = var->varcollid;
! retval->location = var->location;
return retval;
}
*************** replace_outer_var(PlannerInfo *root, Var
*** 166,173 ****
* Generate a Param node to replace the given Var, which will be supplied
* from an upper NestLoop join node.
*
! * Because we allow nestloop and subquery Params to alias each other,
! * this is effectively the same as replace_outer_var, except that we expect
* the Var to be local to the current query level.
*/
Param *
--- 164,170 ----
* 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 *r
*** 186,199 ****
retval->paramtype = var->vartype;
retval->paramtypmod = var->vartypmod;
retval->paramcollid = var->varcollid;
! retval->location = -1;
return retval;
}
/*
! * Select a PARAM_EXEC number to identify the given PlaceHolderVar.
! * If the PlaceHolderVar already has a param slot, return that one.
*
* This is just like assign_param_for_var, except for PlaceHolderVars.
*/
--- 183,197 ----
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.
*/
*************** assign_param_for_placeholdervar(PlannerI
*** 202,226 ****
{
ListCell *ppl;
PlannerParamItem *pitem;
! Index abslevel;
! int i;
! abslevel = root->query_level - phv->phlevelsup;
! /* If there's already a paramlist entry for this same PHV, just use it */
! i = 0;
! foreach(ppl, root->glob->paramlist)
{
pitem = (PlannerParamItem *) lfirst(ppl);
! if (pitem->abslevel == abslevel && IsA(pitem->item, PlaceHolderVar))
{
PlaceHolderVar *pphv = (PlaceHolderVar *) pitem->item;
/* We assume comparing the PHIDs is sufficient */
if (pphv->phid == phv->phid)
! return i;
}
- i++;
}
/* Nope, so make a new one */
--- 200,223 ----
{
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 */
*************** assign_param_for_placeholdervar(PlannerI
*** 233,244 ****
pitem = makeNode(PlannerParamItem);
pitem->item = (Node *) phv;
! pitem->abslevel = abslevel;
! root->glob->paramlist = lappend(root->glob->paramlist, pitem);
! /* i is already the correct list index for the new item */
! return i;
}
/*
--- 230,240 ----
pitem = makeNode(PlannerParamItem);
pitem->item = (Node *) phv;
! pitem->paramId = root->glob->nParamExec++;
! root->plan_params = lappend(root->plan_params, pitem);
! return pitem->paramId;
}
/*
*************** replace_outer_placeholdervar(PlannerInfo
*** 255,264 ****
Assert(phv->phlevelsup > 0 && phv->phlevelsup < root->query_level);
! /*
! * Find the PlaceHolderVar in root->glob->paramlist, or add it if not
! * present.
! */
i = assign_param_for_placeholdervar(root, phv);
retval = makeNode(Param);
--- 251,257 ----
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);
*************** replace_outer_agg(PlannerInfo *root, Agg
*** 308,318 ****
{
Param *retval;
PlannerParamItem *pitem;
! Index abslevel;
! int i;
Assert(agg->agglevelsup > 0 && agg->agglevelsup < root->query_level);
! abslevel = root->query_level - agg->agglevelsup;
/*
* It does not seem worthwhile to try to match duplicate outer aggs. Just
--- 301,313 ----
{
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
*************** replace_outer_agg(PlannerInfo *root, Agg
*** 324,341 ****
pitem = makeNode(PlannerParamItem);
pitem->item = (Node *) agg;
! pitem->abslevel = abslevel;
! root->glob->paramlist = lappend(root->glob->paramlist, pitem);
! i = list_length(root->glob->paramlist) - 1;
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
! retval->paramid = i;
retval->paramtype = agg->aggtype;
retval->paramtypmod = -1;
retval->paramcollid = agg->aggcollid;
! retval->location = -1;
return retval;
}
--- 319,335 ----
pitem = makeNode(PlannerParamItem);
pitem->item = (Node *) agg;
! pitem->paramId = root->glob->nParamExec++;
! 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;
}
*************** replace_outer_agg(PlannerInfo *root, Agg
*** 343,371 ****
/*
* Generate a new Param node that will not conflict with any other.
*
! * This is used to allocate PARAM_EXEC slots for subplan outputs.
*/
static Param *
generate_new_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod,
Oid paramcollation)
{
Param *retval;
- PlannerParamItem *pitem;
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
! retval->paramid = list_length(root->glob->paramlist);
retval->paramtype = paramtype;
retval->paramtypmod = paramtypmod;
retval->paramcollid = paramcollation;
retval->location = -1;
- pitem = makeNode(PlannerParamItem);
- pitem->item = (Node *) retval;
- pitem->abslevel = root->query_level;
-
- root->glob->paramlist = lappend(root->glob->paramlist, pitem);
-
return retval;
}
--- 337,360 ----
/*
* 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 record the PARAM_EXEC slot number as being allocated.
*/
static Param *
generate_new_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod,
Oid paramcollation)
{
Param *retval;
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
! retval->paramid = root->glob->nParamExec++;
retval->paramtype = paramtype;
retval->paramtypmod = paramtypmod;
retval->paramcollid = paramcollation;
retval->location = -1;
return retval;
}
*************** generate_new_param(PlannerInfo *root, Oi
*** 374,390 ****
* 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.
*/
int
SS_assign_special_param(PlannerInfo *root)
{
! Param *param;
!
! /* We generate a Param of datatype INTERNAL */
! param = generate_new_param(root, INTERNALOID, -1, InvalidOid);
! /* ... but the caller only cares about its ID */
! return param->paramid;
}
/*
--- 363,375 ----
* 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)
{
! return root->glob->nParamExec++;
}
/*
*************** make_subplan(PlannerInfo *root, Query *o
*** 445,450 ****
--- 430,436 ----
double tuple_fraction;
Plan *plan;
PlannerInfo *subroot;
+ List *plan_params;
Node *result;
/*
*************** make_subplan(PlannerInfo *root, Query *o
*** 488,493 ****
--- 474,482 ----
else
tuple_fraction = 0.0; /* default behavior */
+ /* plan_params should not be in use in current query level */
+ Assert(root->plan_params == NIL);
+
/*
* Generate the plan for the subquery.
*/
*************** make_subplan(PlannerInfo *root, Query *o
*** 496,503 ****
false, tuple_fraction,
&subroot);
/* And convert to SubPlan or InitPlan format. */
! result = build_subplan(root, plan, subroot,
subLinkType, testexpr, true, isTopQual);
/*
--- 485,496 ----
false, tuple_fraction,
&subroot);
+ /* Isolate the params needed by this specific subplan */
+ plan_params = root->plan_params;
+ root->plan_params = NIL;
+
/* And convert to SubPlan or InitPlan format. */
! result = build_subplan(root, plan, subroot, plan_params,
subLinkType, testexpr, true, isTopQual);
/*
*************** make_subplan(PlannerInfo *root, Query *o
*** 530,535 ****
--- 523,532 ----
false, 0.0,
&subroot);
+ /* Isolate the params needed by this specific subplan */
+ plan_params = root->plan_params;
+ root->plan_params = NIL;
+
/* Now we can check if it'll fit in work_mem */
if (subplan_is_hashable(plan))
{
*************** make_subplan(PlannerInfo *root, Query *o
*** 538,543 ****
--- 535,541 ----
/* OK, convert to SubPlan format. */
hashplan = (SubPlan *) build_subplan(root, plan, subroot,
+ plan_params,
ANY_SUBLINK, newtestexpr,
false, true);
/* Check we got what we expected */
*************** make_subplan(PlannerInfo *root, Query *o
*** 566,579 ****
*/
static Node *
build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot,
SubLinkType subLinkType, Node *testexpr,
bool adjust_testexpr, bool unknownEqFalse)
{
Node *result;
SubPlan *splan;
bool isInitPlan;
! Bitmapset *tmpset;
! int paramid;
/*
* Initialize the SubPlan node. Note plan_id, plan_name, and cost fields
--- 564,577 ----
*/
static Node *
build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot,
+ List *plan_params,
SubLinkType subLinkType, Node *testexpr,
bool adjust_testexpr, bool unknownEqFalse)
{
Node *result;
SubPlan *splan;
bool isInitPlan;
! ListCell *lc;
/*
* Initialize the SubPlan node. Note plan_id, plan_name, and cost fields
*************** build_subplan(PlannerInfo *root, Plan *p
*** 595,630 ****
* Make parParam and args lists of param IDs and expressions that current
* query level will pass to this child plan.
*/
! tmpset = bms_copy(plan->extParam);
! while ((paramid = bms_first_member(tmpset)) >= 0)
{
! PlannerParamItem *pitem = list_nth(root->glob->paramlist, paramid);
!
! if (pitem->abslevel == root->query_level)
! {
! Node *arg;
!
! /*
! * The Var, PlaceHolderVar, or Aggref has already been adjusted to
! * have the correct varlevelsup, phlevelsup, or agglevelsup. We
! * probably don't even need to copy it again, but be safe.
! */
! arg = copyObject(pitem->item);
! /*
! * If it's a PlaceHolderVar or Aggref, its arguments might contain
! * SubLinks, which have not yet been processed (see the comments
! * for SS_replace_correlation_vars). Do that now.
! */
! if (IsA(arg, PlaceHolderVar) ||
! IsA(arg, Aggref))
! arg = SS_process_sublinks(root, arg, false);
! splan->parParam = lappend_int(splan->parParam, paramid);
! splan->args = lappend(splan->args, arg);
! }
}
- bms_free(tmpset);
/*
* Un-correlated or undirect correlated plans of EXISTS, EXPR, ARRAY, or
--- 593,618 ----
* Make parParam and args lists of param IDs and expressions that current
* query level will pass to this child plan.
*/
! foreach(lc, plan_params)
{
! PlannerParamItem *pitem = (PlannerParamItem *) lfirst(lc);
! Node *arg = pitem->item;
! /*
! * The Var, PlaceHolderVar, or Aggref has already been adjusted to
! * have the correct varlevelsup, phlevelsup, or agglevelsup.
! *
! * If it's a PlaceHolderVar or Aggref, its arguments might contain
! * SubLinks, which have not yet been processed (see the comments for
! * SS_replace_correlation_vars). Do that now.
! */
! if (IsA(arg, PlaceHolderVar) ||
! IsA(arg, Aggref))
! arg = SS_process_sublinks(root, arg, false);
! splan->parParam = lappend_int(splan->parParam, pitem->paramId);
! splan->args = lappend(splan->args, arg);
}
/*
* Un-correlated or undirect correlated plans of EXISTS, EXPR, ARRAY, or
*************** SS_process_ctes(PlannerInfo *root)
*** 1045,1053 ****
Plan *plan;
PlannerInfo *subroot;
SubPlan *splan;
- Bitmapset *tmpset;
int paramid;
- Param *prm;
/*
* Ignore SELECT CTEs that are not actually referenced anywhere.
--- 1033,1039 ----
*************** SS_process_ctes(PlannerInfo *root)
*** 1065,1070 ****
--- 1051,1059 ----
*/
subquery = (Query *) copyObject(cte->ctequery);
+ /* plan_params should not be in use in current query level */
+ Assert(root->plan_params == NIL);
+
/*
* Generate the plan for the CTE query. Always plan for full
* retrieval --- we don't have enough info to predict otherwise.
*************** SS_process_ctes(PlannerInfo *root)
*** 1074,1079 ****
--- 1063,1072 ----
cte->cterecursive, 0.0,
&subroot);
+ /* There should not be any side-references in the CTE query */
+ if (root->plan_params)
+ elog(ERROR, "unexpected outer reference in CTE query");
+
/*
* Make a SubPlan node for it. This is just enough unlike
* build_subplan that we can't share code.
*************** SS_process_ctes(PlannerInfo *root)
*** 1093,1127 ****
splan->args = NIL;
/*
! * Make parParam and args lists of param IDs and expressions that
! * current query level will pass to this child plan. Even though this
! * is an initplan, there could be side-references to earlier
! * initplan's outputs, specifically their CTE output parameters.
*/
- tmpset = bms_copy(plan->extParam);
- while ((paramid = bms_first_member(tmpset)) >= 0)
- {
- PlannerParamItem *pitem = list_nth(root->glob->paramlist, paramid);
-
- if (pitem->abslevel == root->query_level)
- {
- prm = (Param *) pitem->item;
- if (!IsA(prm, Param) ||
- prm->paramtype != INTERNALOID)
- elog(ERROR, "bogus local parameter passed to WITH query");
-
- splan->parParam = lappend_int(splan->parParam, paramid);
- splan->args = lappend(splan->args, copyObject(prm));
- }
- }
- bms_free(tmpset);
/*
! * Assign a param to represent the query output. We only really care
! * about reserving a parameter ID number.
*/
! prm = generate_new_param(root, INTERNALOID, -1, InvalidOid);
! splan->setParam = list_make1_int(prm->paramid);
/*
* Add the subplan and its PlannerInfo to the global lists.
--- 1086,1107 ----
splan->args = NIL;
/*
! * The node can't have any inputs (since it's an initplan), so the
! * parParam and args lists remain empty. (It could contain references
! * to earlier CTEs' output param IDs, but CTE outputs are not
! * propagated via the args list.)
*/
/*
! * Assign a param ID to represent the CTE's output. No ordinary
! * "evaluation" of this param slot ever happens, but we use the param
! * ID for setParam/chgParam signaling just as if the CTE plan were
! * returning a simple scalar output. (Also, the executor abuses the
! * ParamExecData slot for this param ID for communication among
! * multiple CteScan nodes that might be scanning this CTE.)
*/
! paramid = SS_assign_special_param(root);
! splan->setParam = list_make1_int(paramid);
/*
* Add the subplan and its PlannerInfo to the global lists.
*************** SS_finalize_plan(PlannerInfo *root, Plan
*** 1932,1938 ****
*initExtParam,
*initSetParam;
Cost initplan_cost;
! int paramid;
ListCell *l;
/*
--- 1912,1918 ----
*initExtParam,
*initSetParam;
Cost initplan_cost;
! PlannerInfo *proot;
ListCell *l;
/*
*************** SS_finalize_plan(PlannerInfo *root, Plan
*** 1964,1994 ****
/*
* 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. Likewise, special parameters that are generated by
* nodes such as ModifyTable are handled within finalize_plan.)
- *
- * 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, or might be nestloop params that won't be passed down at all.
- * 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 = bms_copy(initSetParam);
! paramid = 0;
! foreach(l, root->glob->paramlist)
{
! PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l);
!
! if (pitem->abslevel < root->query_level)
{
! /* valid outer-level parameter */
! valid_params = bms_add_member(valid_params, paramid);
}
! paramid++;
}
/*
--- 1944,1979 ----
/*
* 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.)
*/
valid_params = bms_copy(initSetParam);
! for (proot = root->parent_root; proot != NULL; proot = proot->parent_root)
{
! /* Include ordinary Var/PHV/Aggref params */
! foreach(l, proot->plan_params)
{
! PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l);
!
! valid_params = bms_add_member(valid_params, pitem->paramId);
}
+ /* Include any outputs of outer-level initPlans */
+ foreach(l, proot->init_plans)
+ {
+ SubPlan *initsubplan = (SubPlan *) lfirst(l);
+ ListCell *l2;
! foreach(l2, initsubplan->setParam)
! {
! valid_params = bms_add_member(valid_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);
}
/*
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 3d1fcdc16c94fc314c8b5af05399794782a1bbbe..44b5d6758e7ef49ebb3816996f47cd6dbac208a7 100644
*** a/src/backend/optimizer/prep/prepjointree.c
--- b/src/backend/optimizer/prep/prepjointree.c
*************** pull_up_simple_subquery(PlannerInfo *roo
*** 799,804 ****
--- 799,805 ----
subroot->glob = root->glob;
subroot->query_level = root->query_level;
subroot->parent_root = root->parent_root;
+ subroot->plan_params = NIL;
subroot->planner_cxt = CurrentMemoryContext;
subroot->init_plans = NIL;
subroot->cte_plan_ids = NIL;
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 94373b087c3ec2fe572a51e34321bc773c66ec20..c66ea7bc6f44290c2fc4117127a138b18e52cf23 100644
*** a/src/backend/optimizer/prep/prepunion.c
--- b/src/backend/optimizer/prep/prepunion.c
*************** recurse_set_operations(Node *setOp, Plan
*** 238,243 ****
--- 238,246 ----
*/
rel = build_simple_rel(root, rtr->rtindex, RELOPT_BASEREL);
+ /* plan_params should not be in use in current query level */
+ Assert(root->plan_params == NIL);
+
/*
* Generate plan for primitive subquery
*/
*************** recurse_set_operations(Node *setOp, Plan
*** 250,255 ****
--- 253,262 ----
rel->subplan = subplan;
rel->subroot = subroot;
+ /* There should not be any side-references in the primitive query */
+ if (root->plan_params)
+ elog(ERROR, "unexpected outer reference in set operation subquery");
+
/*
* Estimate number of groups if caller wants it. If the subquery used
* grouping or aggregation, its output is probably mostly unique
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 3878c3752fef56e43bbe12d8c1613698993d0d1d..f724714e49fe03d34a837cd8edd157664d3098a4 100644
*** a/src/backend/optimizer/util/relnode.c
--- b/src/backend/optimizer/util/relnode.c
*************** build_simple_rel(PlannerInfo *root, int
*** 119,124 ****
--- 119,125 ----
rel->allvisfrac = 0;
rel->subplan = NULL;
rel->subroot = NULL;
+ rel->subplan_params = NIL;
rel->fdwroutine = NULL;
rel->fdw_private = NULL;
rel->baserestrictinfo = NIL;
*************** build_join_rel(PlannerInfo *root,
*** 379,384 ****
--- 380,386 ----
joinrel->allvisfrac = 0;
joinrel->subplan = NULL;
joinrel->subroot = NULL;
+ joinrel->subplan_params = NIL;
joinrel->fdwroutine = NULL;
joinrel->fdw_private = NULL;
joinrel->baserestrictinfo = NIL;
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index af9425ad9b309fbecd65d1a83a229ddfd447f382..2b2742d7ef5bbc1ae2ddd3e2bf81f986e80524d9 100644
*** a/src/include/nodes/relation.h
--- b/src/include/nodes/relation.h
*************** typedef struct PlannerGlobal
*** 75,82 ****
ParamListInfo boundParams; /* Param values provided to planner() */
- List *paramlist; /* to keep track of cross-level Params */
-
List *subplans; /* Plans for SubPlan nodes */
List *subroots; /* PlannerInfos for SubPlan nodes */
--- 75,80 ----
*************** typedef struct PlannerGlobal
*** 93,98 ****
--- 91,98 ----
List *invalItems; /* other dependencies, as PlanInvalItems */
+ int nParamExec; /* number of PARAM_EXEC Params used */
+
Index lastPHId; /* highest PlaceHolderVar ID assigned */
Index lastRowMarkId; /* highest PlanRowMark ID assigned */
*************** typedef struct PlannerInfo
*** 127,132 ****
--- 127,134 ----
struct PlannerInfo *parent_root; /* NULL at outermost Query */
+ List *plan_params; /* list of PlannerParamItems, see below */
+
/*
* simple_rel_array holds pointers to "base rels" and "other rels" (see
* comments for RelOptInfo for more info). It is indexed by rangetable
*************** typedef struct PlannerInfo
*** 344,349 ****
--- 346,352 ----
* allvisfrac - fraction of disk pages that are marked all-visible
* subplan - plan for subquery (NULL if it's not a subquery)
* subroot - PlannerInfo for subquery (NULL if it's not a subquery)
+ * subplan_params - list of PlannerParamItems to be passed to subquery
* fdwroutine - function hooks for FDW, if foreign table (else NULL)
* fdw_private - private state for FDW, if foreign table (else NULL)
*
*************** typedef struct RelOptInfo
*** 436,441 ****
--- 439,445 ----
/* use "struct Plan" to avoid including plannodes.h here */
struct Plan *subplan; /* if subquery */
PlannerInfo *subroot; /* if subquery */
+ List *subplan_params; /* if subquery */
/* use "struct FdwRoutine" to avoid including fdwapi.h here */
struct FdwRoutine *fdwroutine; /* if foreign table */
void *fdw_private; /* if foreign table */
*************** typedef struct MinMaxAggInfo
*** 1507,1529 ****
} MinMaxAggInfo;
/*
! * glob->paramlist keeps track of the PARAM_EXEC slots that we have decided
! * we need for the query. At runtime these slots are used to pass values
! * around from one plan node to another. They can be used to pass values
! * down into subqueries (for outer references in subqueries), or up out of
! * subqueries (for the results of a subplan), or from a NestLoop plan node
! * into its inner relation (when the inner scan is parameterized with values
! * from the outer relation). The n'th entry in the list (n counts from 0)
! * corresponds to Param->paramid = n.
*
! * Each paramlist item shows the absolute query level it is associated with,
! * where the outermost query is level 1 and nested subqueries have higher
! * numbers. The item the parameter slot represents can be one of four kinds:
*
! * A Var: the slot represents a variable of that level that must be passed
* down because subqueries have outer references to it, or must be passed
! * from a NestLoop node of that level to its inner scan. The varlevelsup
! * value in the Var will always be zero.
*
* A PlaceHolderVar: this works much like the Var case, except that the
* entry is a PlaceHolderVar node with a contained expression. The PHV
--- 1511,1536 ----
} MinMaxAggInfo;
/*
! * At runtime, PARAM_EXEC slots are used to pass values around from one plan
! * node to another. They can be used to pass values down into subqueries (for
! * outer references in subqueries), or up out of subqueries (for the results
! * of a subplan), or from a NestLoop plan node into its inner relation (when
! * the inner scan is parameterized with values from the outer relation).
! * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
! * the PARAM_EXEC Params it generates.
*
! * Outer references are managed via root->plan_params, which is a list of
! * PlannerParamItems. While planning a subquery, each parent query level's
! * plan_params contains the values required from it by the current subquery.
! * During create_plan(), we use plan_params to track values that must be
! * passed from outer to inner sides of NestLoop plan nodes.
*
! * The item a PlannerParamItem represents can be one of three kinds:
! *
! * A Var: the slot represents a variable of this level that must be passed
* down because subqueries have outer references to it, or must be passed
! * from a NestLoop node to its inner scan. The varlevelsup value in the Var
! * will always be zero.
*
* A PlaceHolderVar: this works much like the Var case, except that the
* entry is a PlaceHolderVar node with a contained expression. The PHV
*************** typedef struct MinMaxAggInfo
*** 1535,1559 ****
* subquery. The Aggref itself has agglevelsup = 0, and its argument tree
* is adjusted to match in level.
*
- * A Param: the slot holds the result of a subplan (it is a setParam item
- * for that subplan). The absolute level shown for such items corresponds
- * to the parent query of the subplan.
- *
* Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
! * them into one slot, but we do not bother to do this for Aggrefs, and it
! * would be incorrect to do so for Param slots. Duplicate detection is
! * actually *necessary* for NestLoop parameters since it serves to match up
! * the usage of a Param (in the inner scan) with the assignment of the value
! * (in the NestLoop node). This might result in the same PARAM_EXEC slot being
! * used by multiple NestLoop nodes or SubPlan nodes, but no harm is done since
! * the same value would be assigned anyway.
*/
typedef struct PlannerParamItem
{
NodeTag type;
! Node *item; /* the Var, PlaceHolderVar, Aggref, or Param */
! Index abslevel; /* its absolute query level */
} PlannerParamItem;
/*
--- 1542,1568 ----
* subquery. The Aggref itself has agglevelsup = 0, and its argument tree
* is adjusted to match in level.
*
* Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
! * them into one slot, but we do not bother to do that for Aggrefs.
! * The scope of duplicate-elimination only extends across the set of
! * parameters passed from one query level into a single subquery, or for
! * nestloop parameters across the set of nestloop parameters used in a single
! * query level. So there is no possibility of a PARAM_EXEC slot being used
! * for conflicting purposes.
! *
! * In addition, PARAM_EXEC slots are assigned for Params representing outputs
! * from subplans (values that are setParam items for those subplans). These
! * IDs need not be tracked via PlannerParamItems, since we do not need any
! * duplicate-elimination nor later processing of the represented expressions.
! * Instead, we just record the assignment of the slot number by incrementing
! * root->glob->nParamExec.
*/
typedef struct PlannerParamItem
{
NodeTag type;
! Node *item; /* the Var, PlaceHolderVar, or Aggref */
! int paramId; /* its assigned PARAM_EXEC slot number */
} PlannerParamItem;
/*
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