Create executor and planner-backend support for decoupled heap and index

scans, using in-memory tuple ID bitmaps as the intermediary.  The planner
frontend (path creation and cost estimation) is not there yet, so none
of this code can be executed.  I have tested it using some hacked planner
code that is far too ugly to see the light of day, however.  Committing
now so that the bulk of the infrastructure changes go in before the tree
drifts under me.

1 files changed, 34 insertions, 1 deletions

diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index 14b62b80fc8..ec0fc8a29ab 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.115 2005/04/06 16:34:06 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.116 2005/04/19 22:35:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -472,6 +472,39 @@ create_index_path(Query *root,
 }
 
 /*
+ * create_bitmap_heap_path
+ *	  Creates a path node for a bitmap scan.
+ *
+ * 'bitmapqual' is an AND/OR tree of IndexPath nodes.
+ */
+BitmapHeapPath *
+create_bitmap_heap_path(Query *root,
+						RelOptInfo *rel,
+						Node *bitmapqual)
+{
+	BitmapHeapPath *pathnode = makeNode(BitmapHeapPath);
+
+	pathnode->path.pathtype = T_BitmapHeapScan;
+	pathnode->path.parent = rel;
+	pathnode->path.pathkeys = NIL;			/* always unordered */
+
+	pathnode->bitmapqual = bitmapqual;
+
+	/* It's not an innerjoin path. */
+	pathnode->isjoininner = false;
+
+	/*
+	 * The number of rows is the same as the parent rel's estimate, since
+	 * this isn't a join inner indexscan.
+	 */
+	pathnode->rows = rel->rows;
+
+	cost_bitmap_scan(&pathnode->path, root, rel, bitmapqual, false);
+
+	return pathnode;
+}
+
+/*
  * create_tidscan_path
  *	  Creates a path corresponding to a tid_direct scan, returning the
  *	  pathnode.