Allow VACUUM to complete faster by avoiding scanning the indexes when no

rows were removed from the heap by the VACUUM.

Simon Riggs

4 files changed, 46 insertions, 19 deletions

diff --git a/src/backend/access/gist/gistvacuum.c b/src/backend/access/gist/gistvacuum.c
index 31c560a83ad..10bd6cb4dc1 100644
--- a/src/backend/access/gist/gistvacuum.c
+++ b/src/backend/access/gist/gistvacuum.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.11 2005/11/22 18:17:05 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.12 2006/02/11 16:59:08 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -125,7 +125,7 @@ gistVacuumUpdate(GistVacuum *gv, BlockNumber blkno, bool needunion)
 					if (chldtuple.ituplen > 1)
 					{
 						/*
-						 * child was splitted, so we need mark completion
+						 * child was split, so we need mark completion
 						 * insert(split)
 						 */
 						int			j;
@@ -329,9 +329,9 @@ gistVacuumUpdate(GistVacuum *gv, BlockNumber blkno, bool needunion)
 }
 
 /*
- * For usial vacuum just update FSM, for full vacuum
+ * For usual vacuum just update FSM, for full vacuum
  * reforms parent tuples if some of childs was deleted or changed,
- * update invalid tuples (they can exsist from last crash recovery only),
+ * update invalid tuples (they can exist from last crash recovery only),
  * tries to get smaller index
  */
 
@@ -505,10 +505,15 @@ gistbulkdelete(PG_FUNCTION_ARGS)
 			   *ptr;
 	bool		needLock;
 
-	stack = (GistBDItem *) palloc0(sizeof(GistBDItem));
+    if (callback_state)
+    {
+    	stack = (GistBDItem *) palloc0(sizeof(GistBDItem));
 
-	stack->blkno = GIST_ROOT_BLKNO;
-	needFullVacuum = false;
+	   stack->blkno = GIST_ROOT_BLKNO;
+	   needFullVacuum = false;
+    }
+    else
+        stack = NULL;
 
 	while (stack)
 	{
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 3a01109125f..548901a9be4 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/hash/hash.c,v 1.83 2006/01/25 23:26:11 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/hash/hash.c,v 1.84 2006/02/11 16:59:09 momjian Exp $
  *
  * NOTES
  *	  This file contains only the public interface routines.
@@ -496,6 +496,17 @@ hashbulkdelete(PG_FUNCTION_ARGS)
 	tuples_removed = 0;
 	num_index_tuples = 0;
 
+	/* return statistics */
+	num_pages = RelationGetNumberOfBlocks(rel);
+
+	result = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
+	result->num_pages = num_pages;
+
+    if (!callback_state)
+    {
+        	PG_RETURN_POINTER(result);
+    }
+
 	/*
 	 * Read the metapage to fetch original bucket and tuple counts.  Also, we
 	 * keep a copy of the last-seen metapage so that we can use its
@@ -644,11 +655,6 @@ loop_top:
 
 	_hash_wrtbuf(rel, metabuf);
 
-	/* return statistics */
-	num_pages = RelationGetNumberOfBlocks(rel);
-
-	result = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
-	result->num_pages = num_pages;
 	result->num_index_tuples = num_index_tuples;
 	result->tuples_removed = tuples_removed;
 
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index c1e61ff2bda..0365ae79424 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/index/indexam.c,v 1.87 2005/12/03 05:51:00 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/index/indexam.c,v 1.88 2006/02/11 16:59:09 momjian Exp $
  *
  * INTERFACE ROUTINES
  *		index_open		- open an index relation by relation OID
@@ -685,6 +685,11 @@ index_getmulti(IndexScanDesc scan,
  *		callback routine tells whether a given main-heap tuple is
  *		to be deleted
  *
+ *      passing NULL callback_state can be interpreted by the 
+ *      index access method as meaning that the index does not need
+ *      to be scanned in logical sequence to remove rows for this call
+ *      index_vacuum_cleanup is always required after this, however.
+ * 
  *		return value is an optional palloc'd struct of statistics
  * ----------------
  */
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 45f49c0b2bd..e757c4adad1 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.136 2006/01/25 23:04:20 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.137 2006/02/11 16:59:09 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -543,8 +543,9 @@ btbulkdelete(PG_FUNCTION_ARGS)
 	double		num_index_tuples;
 	OffsetNumber deletable[MaxOffsetNumber];
 	int			ndeletable;
-	Buffer		buf;
+	Buffer		buf = NULL;
 	BlockNumber num_pages;
+    bool        scanindex = true;
 
 	tuples_removed = 0;
 	num_index_tuples = 0;
@@ -565,8 +566,15 @@ btbulkdelete(PG_FUNCTION_ARGS)
 	 * skip obtaining exclusive lock on empty pages though, since no indexscan
 	 * could be stopped on those.
 	 */
-	buf = _bt_get_endpoint(rel, 0, false);
-	if (BufferIsValid(buf))		/* check for empty index */
+    if (callback_state)
+    {
+    	buf = _bt_get_endpoint(rel, 0, false);
+        scanindex = BufferIsValid(buf); /* check for empty index */
+    }
+    else
+        scanindex = false;
+
+	if (scanindex)	
 	{
 		for (;;)
 		{
@@ -649,7 +657,10 @@ btbulkdelete(PG_FUNCTION_ARGS)
 
 	result = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
 	result->num_pages = num_pages;
-	result->num_index_tuples = num_index_tuples;
+    if (scanindex)
+    	result->num_index_tuples = num_index_tuples;
+    else
+        result->num_index_tuples = -1;
 	result->tuples_removed = tuples_removed;
 
 	PG_RETURN_POINTER(result);