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, 42 insertions, 14 deletions

diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 33e28413439..568bf8ee1e4 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.135 2002/10/14 22:14:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.136 2002/11/06 00:00:44 tgl Exp $
  *
  * NOTES
  *	  Most of the read functions for plan nodes are tested. (In fact, they
@@ -696,17 +696,6 @@ _readSort(void)
 	return local_node;
 }
 
-static Agg *
-_readAgg(void)
-{
-	Agg		   *local_node;
-
-	local_node = makeNode(Agg);
-	_getPlan((Plan *) local_node);
-
-	return local_node;
-}
-
 /* ----------------
  *		_readHash
  *
@@ -1881,6 +1870,45 @@ _readAppendPath(void)
 }
 
 /* ----------------
+ *		_readResultPath
+ *
+ *	ResultPath is a subclass of Path.
+ * ----------------
+ */
+static ResultPath *
+_readResultPath(void)
+{
+	ResultPath *local_node;
+	char	   *token;
+	int			length;
+
+	local_node = makeNode(ResultPath);
+
+	token = pg_strtok(&length); /* get :pathtype */
+	token = pg_strtok(&length); /* now read it */
+	local_node->path.pathtype = atoi(token);
+
+	token = pg_strtok(&length); /* get :startup_cost */
+	token = pg_strtok(&length); /* now read it */
+	local_node->path.startup_cost = (Cost) atof(token);
+
+	token = pg_strtok(&length); /* get :total_cost */
+	token = pg_strtok(&length); /* now read it */
+	local_node->path.total_cost = (Cost) atof(token);
+
+	token = pg_strtok(&length); /* get :pathkeys */
+	local_node->path.pathkeys = nodeRead(true); /* now read it */
+
+	token = pg_strtok(&length); /* get :subpath */
+	local_node->subpath = nodeRead(true);		/* now read it */
+
+	token = pg_strtok(&length); /* get :constantqual */
+	local_node->constantqual = nodeRead(true);		/* now read it */
+
+	return local_node;
+}
+
+/* ----------------
  *		_readNestPath
  *
  *	NestPath is a subclass of Path
@@ -2196,8 +2224,6 @@ parsePlanString(void)
 		return_value = _readFromExpr();
 	else if (length == 8 && strncmp(token, "JOINEXPR", length) == 0)
 		return_value = _readJoinExpr();
-	else if (length == 3 && strncmp(token, "AGG", length) == 0)
-		return_value = _readAgg();
 	else if (length == 4 && strncmp(token, "HASH", length) == 0)
 		return_value = _readHash();
 	else if (length == 6 && strncmp(token, "RESDOM", length) == 0)
@@ -2240,6 +2266,8 @@ parsePlanString(void)
 		return_value = _readTidPath();
 	else if (length == 10 && strncmp(token, "APPENDPATH", length) == 0)
 		return_value = _readAppendPath();
+	else if (length == 10 && strncmp(token, "RESULTPATH", length) == 0)
+		return_value = _readResultPath();
 	else if (length == 8 && strncmp(token, "NESTPATH", length) == 0)
 		return_value = _readNestPath();
 	else if (length == 9 && strncmp(token, "MERGEPATH", length) == 0)