Allow GIN's extractQuery method to signal that nothing can satisfy the query.

In this case extractQuery should returns -1 as nentries. This changes
prototype of extractQuery method to use int32* instead of uint32* for
nentries argument.
Based on that gincostestimate may see two corner cases: nothing will be found
or seqscan should be used.

Per proposal at http://archives.postgresql.org/pgsql-hackers/2007-01/msg01581.php

PS tsearch_core patch should be sightly modified to support changes, but I'm
waiting a verdict about reviewing of tsearch_core patch.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c
index a7ded0c47f..3a17233ba8 100644
--- a/src/backend/access/gin/gininsert.c
+++ b/src/backend/access/gin/gininsert.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.6 2007/01/05 22:19:21 momjian Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.7 2007/01/31 15:09:45 teodor Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -203,7 +203,7 @@ static uint32
 ginHeapTupleBulkInsert(GinBuildState *buildstate, Datum value, ItemPointer heapptr)
 {
 	Datum	   *entries;
-	uint32		nentries;
+	int32		nentries;
 	MemoryContext oldCtx;
 
 	oldCtx = MemoryContextSwitchTo(buildstate->funcCtx);
@@ -356,7 +356,7 @@ static uint32
 ginHeapTupleInsert(Relation index, GinState *ginstate, Datum value, ItemPointer item)
 {
 	Datum	   *entries;
-	uint32		i,
+	int32		i,
 				nentries;
 
 	entries = extractEntriesSU(ginstate, value, &nentries);