Track in the plan the types associated with PARAM_EXEC parameters.

Up until now, we only tracked the number of parameters, which was
sufficient to allocate an array of Datums of the appropriate size,
but not sufficient to, for example, know how to serialize a Datum
stored in one of those slots.  An upcoming patch wants to do that,
so add this tracking to make it possible.

Patch by me, reviewed by Tom Lane and Amit Kapila.

Discussion: http://postgr.es/m/CA+TgmoYqpxDKn8koHdW8BEKk8FMUL0=e8m2Qe=M+r0UBjr3tuQ@mail.gmail.com

1 files changed, 26 insertions, 9 deletions

diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 8f75fa98edc..2e3abeea3d0 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -131,7 +131,9 @@ assign_param_for_var(PlannerInfo *root, Var *var)
 
 	pitem = makeNode(PlannerParamItem);
 	pitem->item = (Node *) var;
-	pitem->paramId = root->glob->nParamExec++;
+	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);
 
@@ -234,7 +236,9 @@ assign_param_for_placeholdervar(PlannerInfo *root, PlaceHolderVar *phv)
 
 	pitem = makeNode(PlannerParamItem);
 	pitem->item = (Node *) phv;
-	pitem->paramId = root->glob->nParamExec++;
+	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);
 
@@ -323,7 +327,9 @@ replace_outer_agg(PlannerInfo *root, Aggref *agg)
 
 	pitem = makeNode(PlannerParamItem);
 	pitem->item = (Node *) agg;
-	pitem->paramId = root->glob->nParamExec++;
+	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);
 
@@ -348,6 +354,7 @@ replace_outer_grouping(PlannerInfo *root, GroupingFunc *grp)
 	Param	   *retval;
 	PlannerParamItem *pitem;
 	Index		levelsup;
+	Oid			ptype;
 
 	Assert(grp->agglevelsup > 0 && grp->agglevelsup < root->query_level);
 
@@ -362,17 +369,20 @@ replace_outer_grouping(PlannerInfo *root, GroupingFunc *grp)
 	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 = root->glob->nParamExec++;
+	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 = exprType((Node *) grp);
+	retval->paramtype = ptype;
 	retval->paramtypmod = -1;
 	retval->paramcollid = InvalidOid;
 	retval->location = grp->location;
@@ -385,7 +395,8 @@ replace_outer_grouping(PlannerInfo *root, GroupingFunc *grp)
  *
  * 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.
+ * 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,
@@ -395,7 +406,9 @@ generate_new_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod,
 
 	retval = makeNode(Param);
 	retval->paramkind = PARAM_EXEC;
-	retval->paramid = root->glob->nParamExec++;
+	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;
@@ -415,7 +428,11 @@ generate_new_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod,
 int
 SS_assign_special_param(PlannerInfo *root)
 {
-	return root->glob->nParamExec++;
+	int			paramId = list_length(root->glob->paramExecTypes);
+
+	root->glob->paramExecTypes = lappend_oid(root->glob->paramExecTypes,
+											 InvalidOid);
+	return paramId;
 }
 
 /*
@@ -2098,7 +2115,7 @@ SS_identify_outer_params(PlannerInfo *root)
 	 * If no parameters have been assigned anywhere in the tree, we certainly
 	 * don't need to do anything here.
 	 */
-	if (root->glob->nParamExec == 0)
+	if (root->glob->paramExecTypes == NIL)
 		return;
 
 	/*