Implement "fastupdate" support for GIN indexes, in which we try to accumulate

multiple index entries in a holding area before adding them to the main index
structure.  This helps because bulk insert is (usually) significantly faster
than retail insert for GIN.

This patch also removes GIN support for amgettuple-style index scans.  The
API defined for amgettuple is difficult to support with fastupdate, and
the previously committed partial-match feature didn't really work with
it either.  We might eventually figure a way to put back amgettuple
support, but it won't happen for 8.4.

catversion bumped because of change in GIN's pg_am entry, and because
the format of GIN indexes changed on-disk (there's a metapage now,
and possibly a pending list).

Teodor Sigaev

1 files changed, 40 insertions, 8 deletions

diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index 222ea677883..e0951a6a4f8 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.20 2009/01/05 17:14:28 alvherre Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.21 2009/03/24 20:17:11 tgl Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -57,7 +57,7 @@ initGinState(GinState *state, Relation index)
 						CurrentMemoryContext);
 
 		/*
-		 * Check opclass capability to do partial match. 
+		 * Check opclass capability to do partial match.
 		 */
 		if ( index_getprocid(index, i+1, GIN_COMPARE_PARTIAL_PROC) != InvalidOid )
 		{
@@ -88,7 +88,7 @@ gintuple_get_attrnum(GinState *ginstate, IndexTuple tuple)
 		bool    isnull;
 
 		/*
-		 * First attribute is always int16, so we can safely use any 
+		 * First attribute is always int16, so we can safely use any
 		 * tuple descriptor to obtain first attribute of tuple
 		 */
 		res = index_getattr(tuple, FirstOffsetNumber, ginstate->tupdesc[0],
@@ -213,6 +213,22 @@ GinInitBuffer(Buffer b, uint32 f)
 	GinInitPage(BufferGetPage(b), f, BufferGetPageSize(b));
 }
 
+void
+GinInitMetabuffer(Buffer b)
+{
+	GinMetaPageData	*metadata;
+	Page 			 page = BufferGetPage(b);
+
+	GinInitPage(page, GIN_META, BufferGetPageSize(b));
+
+	metadata = GinPageGetMeta(page);
+
+	metadata->head = metadata->tail = InvalidBlockNumber;
+	metadata->tailFreeSize = 0;
+	metadata->nPendingPages = 0;
+	metadata->nPendingHeapTuples = 0;
+}
+
 int
 compareEntries(GinState *ginstate, OffsetNumber attnum, Datum a, Datum b)
 {
@@ -315,10 +331,26 @@ ginoptions(PG_FUNCTION_ARGS)
 {
 	Datum		reloptions = PG_GETARG_DATUM(0);
 	bool		validate = PG_GETARG_BOOL(1);
-	bytea	   *result;
+	relopt_value *options;
+	GinOptions *rdopts;
+	int			numoptions;
+	static const relopt_parse_elt tab[] = {
+		{"fastupdate", RELOPT_TYPE_BOOL, offsetof(GinOptions, useFastUpdate)}
+	};
+
+	options = parseRelOptions(reloptions, validate, RELOPT_KIND_GIN,
+							  &numoptions);
+
+	/* if none set, we're done */
+	if (numoptions == 0)
+		PG_RETURN_NULL();
+
+	rdopts = allocateReloptStruct(sizeof(GinOptions), options, numoptions);
+
+	fillRelOptions((void *) rdopts, sizeof(GinOptions), options, numoptions,
+					validate, tab, lengthof(tab));
+
+	pfree(options);
 
-	result = default_reloptions(reloptions, validate, RELOPT_KIND_GIN);
-	if (result)
-		PG_RETURN_BYTEA_P(result);
-	PG_RETURN_NULL();
+	PG_RETURN_BYTEA_P(rdopts);
 }