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Skip ambulkdelete scan if there's nothing to delete and the index is not

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partial.  None of the existing AMs do anything useful except counting
tuples when there's nothing to delete, and we can get a tuple count
from the heap as long as it's not a partial index.  (hash actually can
skip anyway because it maintains a tuple count in the index metapage.)
GIST is not currently able to exploit this optimization because, due to
failure to index NULLs, GIST is always effectively partial.  Possibly
we should fix that sometime.
Simon Riggs w/ some review by Tom Lane.
This commit is contained in:
Tom Lane
2006-02-11 23:31:34 +00:00
parent a02f6ce33b
commit fd267c1ebc
8 changed files with 108 additions and 31 deletions
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73
src/backend/access/gist/gistvacuum.c
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@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.13 2006/02/11 17:14:08 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.14 2006/02/11 23:31:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -25,16 +25,19 @@
#include "storage/freespace.h"
#include "storage/smgr.h"
/* filled by gistbulkdelete, cleared by gistvacuumpcleanup */
static bool needFullVacuum = false;
typedef struct GistBulkDeleteResult
{
IndexBulkDeleteResult std; /* common state */
bool needFullVacuum;
} GistBulkDeleteResult;
typedef struct
{
GISTSTATE giststate;
Relation index;
MemoryContext opCtx;
IndexBulkDeleteResult *result;
GistBulkDeleteResult *result;
} GistVacuum;
typedef struct
@ -44,6 +47,7 @@ typedef struct
bool emptypage;
} ArrayTuple;
static ArrayTuple
gistVacuumUpdate(GistVacuum *gv, BlockNumber blkno, bool needunion)
{
@ -125,7 +129,7 @@ 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;
@ -262,7 +266,7 @@ gistVacuumUpdate(GistVacuum *gv, BlockNumber blkno, bool needunion)
needwrite = true;
res.emptypage = true;
GistPageSetDeleted(page);
gv->result->pages_deleted++;
gv->result->std.pages_deleted++;
}
}
else
@ -329,9 +333,9 @@ 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
*/
@ -340,7 +344,7 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
{
Relation rel = (Relation) PG_GETARG_POINTER(0);
IndexVacuumCleanupInfo *info = (IndexVacuumCleanupInfo *) PG_GETARG_POINTER(1);
IndexBulkDeleteResult *stats = (IndexBulkDeleteResult *) PG_GETARG_POINTER(2);
GistBulkDeleteResult *stats = (GistBulkDeleteResult *) PG_GETARG_POINTER(2);
BlockNumber npages,
blkno;
BlockNumber nFreePages,
@ -377,13 +381,11 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
freeGISTstate(&(gv.giststate));
MemoryContextDelete(gv.opCtx);
}
else if (needFullVacuum)
else if (stats->needFullVacuum)
ereport(NOTICE,
(errmsg("index \"%s\" needs VACUUM FULL or REINDEX to finish crash recovery",
RelationGetRelationName(rel))));
needFullVacuum = false;
if (info->vacuum_full)
needLock = false; /* relation locked with AccessExclusiveLock */
else
@ -438,23 +440,30 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
if (lastBlock > lastFilledBlock)
RelationTruncate(rel, lastFilledBlock + 1);
stats->pages_removed = lastBlock - lastFilledBlock;
stats->std.pages_removed = lastBlock - lastFilledBlock;
}
RecordIndexFreeSpace(&rel->rd_node, nFreePages, freePages);
pfree(freePages);
/* return statistics */
stats->pages_free = nFreePages;
stats->std.pages_free = nFreePages;
if (needLock)
LockRelationForExtension(rel, ExclusiveLock);
stats->num_pages = RelationGetNumberOfBlocks(rel);
stats->std.num_pages = RelationGetNumberOfBlocks(rel);
if (needLock)
UnlockRelationForExtension(rel, ExclusiveLock);
if (info->vacuum_full)
UnlockRelation(rel, AccessExclusiveLock);
/* if gistbulkdelete skipped the scan, use heap's tuple count */
if (stats->std.num_index_tuples < 0)
{
Assert(info->num_heap_tuples >= 0);
stats->std.num_index_tuples = info->num_heap_tuples;
}
PG_RETURN_POINTER(stats);
}
@ -500,15 +509,33 @@ gistbulkdelete(PG_FUNCTION_ARGS)
Relation rel = (Relation) PG_GETARG_POINTER(0);
IndexBulkDeleteCallback callback = (IndexBulkDeleteCallback) PG_GETARG_POINTER(1);
void *callback_state = (void *) PG_GETARG_POINTER(2);
IndexBulkDeleteResult *result = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
GistBulkDeleteResult *result;
GistBDItem *stack,
*ptr;
bool needLock;
stack = (GistBDItem *) palloc0(sizeof(GistBDItem));
result = (GistBulkDeleteResult *) palloc0(sizeof(GistBulkDeleteResult));
stack->blkno = GIST_ROOT_BLKNO;
needFullVacuum = false;
/*
* We can skip the scan entirely if there's nothing to delete (indicated
* by callback_state == NULL) and the index isn't partial. For a partial
* index we must scan in order to derive a trustworthy tuple count.
*
* XXX as of PG 8.2 this is dead code because GIST indexes are always
* effectively partial ... but keep it anyway in case our null-handling
* gets fixed.
*/
if (callback_state || vac_is_partial_index(rel))
{
stack = (GistBDItem *) palloc0(sizeof(GistBDItem));
stack->blkno = GIST_ROOT_BLKNO;
}
else
{
/* skip scan and set flag for gistvacuumcleanup */
stack = NULL;
result->std.num_index_tuples = -1;
}
while (stack)
{
@ -561,11 +588,11 @@ gistbulkdelete(PG_FUNCTION_ARGS)
i--;
maxoff--;
ntodelete++;
result->tuples_removed += 1;
result->std.tuples_removed += 1;
Assert(maxoff == PageGetMaxOffsetNumber(page));
}
else
result->num_index_tuples += 1;
result->std.num_index_tuples += 1;
}
if (ntodelete)
@ -615,7 +642,7 @@ gistbulkdelete(PG_FUNCTION_ARGS)
stack->next = ptr;
if (GistTupleIsInvalid(idxtuple))
needFullVacuum = true;
result->needFullVacuum = true;
}
}
@ -634,7 +661,7 @@ gistbulkdelete(PG_FUNCTION_ARGS)
if (needLock)
LockRelationForExtension(rel, ExclusiveLock);
result->num_pages = RelationGetNumberOfBlocks(rel);
result->std.num_pages = RelationGetNumberOfBlocks(rel);
if (needLock)
UnlockRelationForExtension(rel, ExclusiveLock);