Fix problems with grouping/aggregation in queries that use

inheritance ... basically it was completely busted :-(

Author: tglsfdc

src/backend/optimizer/plan/planner.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.54 1999/05/25 16:09:37 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.55 1999/06/06 17:38:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -122,14 +122,36 @@ union_planner(Query *parse)
 	}
 	else if ((rt_index = first_inherit_rt_entry(rangetable)) != -1)
 	{
-		if (parse->rowMark != NULL)
-			elog(ERROR, "SELECT FOR UPDATE is not supported for inherit queries");
-		result_plan = (Plan *) plan_inherit_queries(parse, rt_index);
-		/* XXX do we need to do this? bjm 12/19/97 */
+		List	   *sub_tlist;
+
+		/*
+		 * Generate appropriate target list for subplan; may be different
+		 * from tlist if grouping or aggregation is needed.
+		 */
+		sub_tlist = make_subplanTargetList(parse, tlist, &groupColIdx);
+
+		/*
+		 * Recursively plan the subqueries needed for inheritance
+		 */
+		result_plan = (Plan *) plan_inherit_queries(parse, sub_tlist,
+													rt_index);
+
+		/*
+		 * Fix up outer target list.  NOTE: unlike the case for non-inherited
+		 * query, we pass the unfixed tlist to subplans, which do their own
+		 * fixing.  But we still want to fix the outer target list afterwards.
+		 * I *think* this is correct --- doing the fix before recursing is
+		 * definitely wrong, because preprocess_targetlist() will do the
+		 * wrong thing if invoked twice on the same list. Maybe that is a bug?
+		 * tgl 6/6/99
+		 */
 		tlist = preprocess_targetlist(tlist,
 									  parse->commandType,
 									  parse->resultRelation,
 									  parse->rtable);
+
+		if (parse->rowMark != NULL)
+			elog(ERROR, "SELECT FOR UPDATE is not supported for inherit queries");
 	}
 	else
 	{

src/backend/optimizer/plan/setrefs.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.49 1999/05/26 12:55:28 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.50 1999/06/06 17:38:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,6 @@ static Var *replace_joinvar_refs(Var *var,
 static List *tlist_noname_references(Oid nonameid, List *tlist);
 static bool OperandIsInner(Node *opnd, int inner_relid);
 static List *pull_agg_clause(Node *clause);
-static Node *del_agg_clause(Node *clause);
 static void set_result_tlist_references(Result *resultNode);
 static void replace_vars_with_subplan_refs(Node *clause,
 							   Index subvarno,
@@ -874,94 +873,6 @@ pull_agg_clause(Node *clause)
 }
 
 
-/*
- * del_agg_tlist_references
- *	  Remove the Agg nodes from the target list
- *	  We do this so inheritance only does aggregates in the upper node
- */
-void
-del_agg_tlist_references(List *tlist)
-{
-	List	   *tl;
-
-	foreach(tl, tlist)
-	{
-		TargetEntry *tle = lfirst(tl);
-
-		tle->expr = del_agg_clause(tle->expr);
-	}
-}
-
-static Node *
-del_agg_clause(Node *clause)
-{
-	List	   *t;
-
-	if (clause == NULL)
-		return clause;
-
-	if (IsA(clause, Var))
-		return clause;
-	else if (is_funcclause(clause))
-	{
-
-		/*
-		 * This is a function. Recursively call this routine for its
-		 * arguments...
-		 */
-		foreach(t, ((Expr *) clause)->args)
-			lfirst(t) = del_agg_clause(lfirst(t));
-	}
-	else if (IsA(clause, Aggref))
-	{
-
-		/* here is the real action, to remove the Agg node */
-		return del_agg_clause(((Aggref *) clause)->target);
-
-	}
-	else if (IsA(clause, ArrayRef))
-	{
-		ArrayRef   *aref = (ArrayRef *) clause;
-
-		/*
-		 * This is an arrayref. Recursively call this routine for its
-		 * expression and its index expression...
-		 */
-		foreach(t, aref->refupperindexpr)
-			lfirst(t) = del_agg_clause(lfirst(t));
-		foreach(t, aref->reflowerindexpr)
-			lfirst(t) = del_agg_clause(lfirst(t));
-		aref->refexpr = del_agg_clause(aref->refexpr);
-		aref->refassgnexpr = del_agg_clause(aref->refassgnexpr);
-	}
-	else if (is_opclause(clause))
-	{
-
-		/*
-		 * This is an operator. Recursively call this routine for both its
-		 * left and right operands
-		 */
-		Node	   *left = (Node *) get_leftop((Expr *) clause);
-		Node	   *right = (Node *) get_rightop((Expr *) clause);
-
-		if (left != (Node *) NULL)
-			left = del_agg_clause(left);
-		if (right != (Node *) NULL)
-			right = del_agg_clause(right);
-	}
-	else if (IsA(clause, Param) ||IsA(clause, Const))
-		return clause;
-	else
-	{
-
-		/*
-		 * Ooops! we can not handle that!
-		 */
-		elog(ERROR, "del_agg_clause: Can not handle this tlist!\n");
-	}
-	return NULL;
-}
-
 /*
  * check_having_for_ungrouped_vars takes the havingQual and the list of
  * GROUP BY clauses and checks for subplans in the havingQual that are being

src/backend/optimizer/prep/prepunion.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.31 1999/05/25 16:09:47 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.32 1999/06/06 17:38:11 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -35,7 +35,7 @@
 #include "optimizer/planmain.h"
 
 static List *plan_inherit_query(Relids relids, Index rt_index,
-				   RangeTblEntry *rt_entry, Query *parse,
+				   RangeTblEntry *rt_entry, Query *parse, List *tlist,
 				   List **union_rtentriesPtr);
 static RangeTblEntry *new_rangetable_entry(Oid new_relid,
 					 RangeTblEntry *old_entry);
@@ -208,32 +208,46 @@ plan_union_queries(Query *parse)
  *
  *	  Plans the queries for a given parent relation.
  *
- * Returns a list containing a list of plans and a list of rangetable
- * entries to be inserted into an APPEND node.
- * XXX - what exactly does this mean, look for make_append
+ * Inputs:
+ *	parse = parent parse tree
+ *	tlist = target list for inheritance subqueries (not same as parent's!)
+ *	rt_index = rangetable index for current inheritance item
+ *
+ * Returns an APPEND node that forms the result of performing the given
+ * query for each member relation of the inheritance group.
+ *
+ * If grouping, aggregation, or sorting is specified in the parent plan,
+ * the subplans should not do any of those steps --- we must do those
+ * operations just once above the APPEND node.  The given tlist has been
+ * modified appropriately to remove group/aggregate expressions, but the
+ * Query node still has the relevant fields set.  We remove them in the
+ * copies used for subplans (see plan_inherit_query).
+ *
+ * NOTE: this can be invoked recursively if more than one inheritance wildcard
+ * is present.  At each level of recursion, the first wildcard remaining in
+ * the rangetable is expanded.
  */
 Append *
-plan_inherit_queries(Query *parse, Index rt_index)
+plan_inherit_queries(Query *parse, List *tlist, Index rt_index)
 {
-	List	   *union_plans = NIL;
-
 	List	   *rangetable = parse->rtable;
 	RangeTblEntry *rt_entry = rt_fetch(rt_index, rangetable);
 	List	   *inheritrtable = NIL;
-	List	   *union_relids = NIL;
+	List	   *union_relids;
+	List	   *union_plans;
 
 	union_relids = find_all_inheritors(lconsi(rt_entry->relid,
 											  NIL),
 									   NIL);
 
 	/*
 	 * Remove the flag for this relation, since we're about to handle it
-	 * (do it before recursing!). XXX destructive parse tree change
+	 * (do it before recursing!). XXX destructive change to parent parse tree
 	 */
-	rt_fetch(rt_index, rangetable)->inh = false;
+	rt_entry->inh = false;
 
 	union_plans = plan_inherit_query(union_relids, rt_index, rt_entry,
-									 parse, &inheritrtable);
+									 parse, tlist, &inheritrtable);
 
 	return (make_append(union_plans,
 						NULL,
@@ -252,11 +266,12 @@ plan_inherit_query(Relids relids,
 				   Index rt_index,
 				   RangeTblEntry *rt_entry,
 				   Query *root,
+				   List *tlist,
 				   List **union_rtentriesPtr)
 {
-	List	   *i;
 	List	   *union_plans = NIL;
 	List	   *union_rtentries = NIL;
+	List	   *i;
 
 	foreach(i, relids)
 	{
@@ -268,19 +283,21 @@ plan_inherit_query(Relids relids,
 												new_rt_entry);
 
 		/*
-		 * reset the uniqueflag and sortclause in parse tree root, so that
-		 * sorting will only be done once after append
+		 * Insert the desired simplified tlist into the subquery
+		 */
+		new_root->targetList = copyObject(tlist);
+
+		/*
+		 * Clear the sorting and grouping qualifications in the subquery,
+		 * so that sorting will only be done once after append
 		 */
 		new_root->uniqueFlag = NULL;
 		new_root->sortClause = NULL;
 		new_root->groupClause = NULL;
 		new_root->havingQual = NULL;
+		new_root->hasAggs = false; /* shouldn't be any left ... */
 
-		if (new_root->hasAggs)
-		{
-			new_root->hasAggs = false;
-			del_agg_tlist_references(new_root->targetList);
-		}
+		/* Fix attribute numbers as necessary */
 		fix_parsetree_attnums(rt_index,
 							  rt_entry->relid,
 							  relid,
@@ -346,7 +363,7 @@ int
 first_inherit_rt_entry(List *rangetable)
 {
 	int			count = 0;
-	List	   *temp = NIL;
+	List	   *temp;
 
 	foreach(temp, rangetable)
 	{
@@ -393,8 +410,8 @@ static Query *
 subst_rangetable(Query *root, Index index, RangeTblEntry *new_entry)
 {
 	Query	   *new_root = copyObject(root);
-	List	   *temp = NIL;
-	int			i = 0;
+	List	   *temp;
+	int			i;
 
 	for (temp = new_root->rtable, i = 1; i < index; temp = lnext(temp), i++)
 		;
@@ -403,6 +420,15 @@ subst_rangetable(Query *root, Index index, RangeTblEntry *new_entry)
 	return new_root;
 }
 
+/*
+ * Adjust varnos for child tables.  This routine makes it possible for
+ * child tables to have different column positions for the "same" attribute
+ * as a parent, which helps ALTER TABLE ADD COLUMN.  Unfortunately this isn't
+ * nearly enough to make it work transparently; there are other places where
+ * things fall down if children and parents don't have the same column numbers
+ * for inherited attributes.  It'd be better to rip this code out and fix
+ * ALTER TABLE...
+ */
 static void
 fix_parsetree_attnums_nodes(Index rt_index,
 							Oid old_relid,
@@ -433,16 +459,11 @@ fix_parsetree_attnums_nodes(Index rt_index,
 		case T_Var:
 			{
 				Var		   *var = (Var *) node;
-				Oid			old_typeid,
-							new_typeid;
-
-				old_typeid = old_relid;
-				new_typeid = new_relid;
 
 				if (var->varno == rt_index && var->varattno != 0)
 				{
-					var->varattno = get_attnum(new_typeid,
-								 get_attname(old_typeid, var->varattno));
+					var->varattno = get_attnum(new_relid,
+								 get_attname(old_relid, var->varattno));
 				}
 			}
 			break;

src/include/optimizer/planmain.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: planmain.h,v 1.27 1999/05/26 12:56:36 momjian Exp $
+ * $Id: planmain.h,v 1.28 1999/06/06 17:38:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -58,7 +58,6 @@ extern void replace_tlist_with_subplan_refs(List *tlist,
 								Index subvarno,
 								List *subplanTargetList);
 extern bool set_agg_tlist_references(Agg *aggNode);
-extern void del_agg_tlist_references(List *tlist);
 extern void check_having_for_ungrouped_vars(Node *clause,
 								List *groupClause,
 								List *targetList);

src/include/optimizer/prep.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: prep.h,v 1.14 1999/02/13 23:21:52 momjian Exp $
+ * $Id: prep.h,v 1.15 1999/06/06 17:38:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,20 +17,23 @@
 #include <nodes/parsenodes.h>
 
 /*
- * prototypes for prepqual.h
+ * prototypes for prepqual.c
  */
 extern List *cnfify(Expr *qual, bool removeAndFlag);
 
 /*
- * prototypes for preptlist.h
+ * prototypes for preptlist.c
  */
 extern List *preprocess_targetlist(List *tlist, int command_type,
 					  Index result_relation, List *range_table);
 
+/*
+ * prototypes for prepunion.c
+ */
 extern List *find_all_inheritors(List *unexamined_relids,
 					List *examined_relids);
 extern int	first_inherit_rt_entry(List *rangetable);
 extern Append *plan_union_queries(Query *parse);
-extern Append *plan_inherit_queries(Query *parse, Index rt_index);
+extern Append *plan_inherit_queries(Query *parse, List *tlist, Index rt_index);
 
 #endif	 /* PREP_H */