Remove RelationGetBufferWithBuffer(), which is horribly confused about

appropriate pin-count manipulation, and instead use ReleaseAndReadBuffer.
Make use of the fact that the passed-in buffer (if there is one) must
be pinned to avoid grabbing the bufmgr spinlock when we are able to
return this same buffer.  Eliminate unnecessary 'previous tuple' and
'next tuple' fields of HeapScanDesc and IndexScanDesc, thereby removing
a whole lot of bookkeeping from heap_getnext() and related routines.

1 files changed, 1 insertions, 39 deletions

diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 13499eef0a8..ee9cea6646c 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.26 2001/01/24 19:42:48 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.27 2001/06/09 18:16:56 tgl Exp $
  *
  * NOTES
  *	  many of the old access method routines have been turned into
@@ -107,12 +107,8 @@ RelationGetIndexScan(Relation relation,
 	scan->opaque = NULL;
 	scan->numberOfKeys = numberOfKeys;
 
-	ItemPointerSetInvalid(&scan->previousItemData);
 	ItemPointerSetInvalid(&scan->currentItemData);
-	ItemPointerSetInvalid(&scan->nextItemData);
-	ItemPointerSetInvalid(&scan->previousMarkData);
 	ItemPointerSetInvalid(&scan->currentMarkData);
-	ItemPointerSetInvalid(&scan->nextMarkData);
 
 	/*
 	 * mark cached function lookup data invalid; it will be set on first
@@ -176,9 +172,7 @@ IndexScanRestart(IndexScanDesc scan,
 	if (!IndexScanIsValid(scan))
 		elog(ERROR, "IndexScanRestart: invalid scan");
 
-	ItemPointerSetInvalid(&scan->previousItemData);
 	ItemPointerSetInvalid(&scan->currentItemData);
-	ItemPointerSetInvalid(&scan->nextItemData);
 
 	if (RelationGetNumberOfBlocks(scan->relation) == 0)
 		scan->flags = ScanUnmarked;
@@ -213,37 +207,7 @@ IndexScanRestart(IndexScanDesc scan,
 void
 IndexScanMarkPosition(IndexScanDesc scan)
 {
-	RetrieveIndexResult result;
-
-	if (scan->flags & ScanUncheckedPrevious)
-	{
-		result = index_getnext(scan, BackwardScanDirection);
-
-		if (result != NULL)
-		{
-			scan->previousItemData = result->index_iptr;
-			pfree(result);
-		}
-		else
-			ItemPointerSetInvalid(&scan->previousItemData);
-	}
-	else if (scan->flags & ScanUncheckedNext)
-	{
-		result = (RetrieveIndexResult)
-			index_getnext(scan, ForwardScanDirection);
-
-		if (result != NULL)
-		{
-			scan->nextItemData = result->index_iptr;
-			pfree(result);
-		}
-		else
-			ItemPointerSetInvalid(&scan->nextItemData);
-	}
-
-	scan->previousMarkData = scan->previousItemData;
 	scan->currentMarkData = scan->currentItemData;
-	scan->nextMarkData = scan->nextItemData;
 
 	scan->flags = 0x0;			/* XXX should have a symbolic name */
 }
@@ -269,9 +233,7 @@ IndexScanRestorePosition(IndexScanDesc scan)
 	if (scan->flags & ScanUnmarked)
 		elog(ERROR, "IndexScanRestorePosition: no mark to restore");
 
-	scan->previousItemData = scan->previousMarkData;
 	scan->currentItemData = scan->currentMarkData;
-	scan->nextItemData = scan->nextMarkData;
 
 	scan->flags = 0x0;			/* XXX should have a symbolic name */
 }