First phase of implementing hash-based grouping/aggregation. An AGG plan

node now does its own grouping of the input rows, and has no need for a
preceding GROUP node in the plan pipeline.  This allows elimination of
the misnamed tuplePerGroup option for GROUP, and actually saves more code
in nodeGroup.c than it costs in nodeAgg.c, as well as being presumably
faster.  Restructure the API of query_planner so that we do not commit to
using a sorted or unsorted plan in query_planner; instead grouping_planner
makes the decision.  (Right now it isn't any smarter than query_planner
was, but that will change as soon as it has the option to select a hash-
based aggregation step.)  Despite all the hackery, no initdb needed since
only in-memory node types changed.

1 files changed, 16 insertions, 2 deletions

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index f0aabc9dc8d..3d916949243 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -5,7 +5,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.89 2002/10/14 04:26:54 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.90 2002/11/06 00:00:43 tgl Exp $
  *
  */
 
@@ -275,7 +275,21 @@ explain_outNode(StringInfo str, Plan *plan, Plan *outer_plan,
 			pname = "Group";
 			break;
 		case T_Agg:
-			pname = "Aggregate";
+			switch (((Agg *) plan)->aggstrategy)
+			{
+				case AGG_PLAIN:
+					pname = "Aggregate";
+					break;
+				case AGG_SORTED:
+					pname = "GroupAggregate";
+					break;
+				case AGG_HASHED:
+					pname = "HashAggregate";
+					break;
+				default:
+					pname = "Aggregate ???";
+					break;
+			}
 			break;
 		case T_Unique:
 			pname = "Unique";