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, 36 insertions, 2 deletions

diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index 4b3c9809b8b..7dd0dce6891 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.78 2002/06/20 20:29:31 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.79 2002/11/06 00:00:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -405,7 +405,6 @@ create_tidscan_path(Query *root, RelOptInfo *rel, List *tideval)
  * create_append_path
  *	  Creates a path corresponding to an Append plan, returning the
  *	  pathnode.
- *
  */
 AppendPath *
 create_append_path(RelOptInfo *rel, List *subpaths)
@@ -434,6 +433,41 @@ create_append_path(RelOptInfo *rel, List *subpaths)
 }
 
 /*
+ * create_result_path
+ *	  Creates a path corresponding to a Result plan, returning the
+ *	  pathnode.
+ */
+ResultPath *
+create_result_path(RelOptInfo *rel, Path *subpath, List *constantqual)
+{
+	ResultPath *pathnode = makeNode(ResultPath);
+
+	pathnode->path.pathtype = T_Result;
+	pathnode->path.parent = rel; /* may be NULL */
+
+	if (subpath)
+		pathnode->path.pathkeys = subpath->pathkeys;
+	else
+		pathnode->path.pathkeys = NIL;
+
+	pathnode->subpath = subpath;
+	pathnode->constantqual = constantqual;
+
+	if (subpath)
+	{
+		pathnode->path.startup_cost = subpath->startup_cost;
+		pathnode->path.total_cost = subpath->total_cost;
+	}
+	else
+	{
+		pathnode->path.startup_cost = 0;
+		pathnode->path.total_cost = cpu_tuple_cost;
+	}
+
+	return pathnode;
+}
+
+/*
  * create_subqueryscan_path
  *	  Creates a path corresponding to a sequential scan of a subquery,
  *	  returning the pathnode.