提交 b2735fcd 编写于 作者: T Tom Lane

Performance improvement for MultiRecordFreeSpace on large relations ---

avoid O(N^2) behavior.  Problem noted and fixed by Stephen Marshall <smarshall@wsicorp.com>,
with some help from Tom Lane.
上级 de96cd5e
......@@ -13,7 +13,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.237 2002/09/04 20:31:16 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.238 2002/09/20 19:56:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -1321,9 +1321,10 @@ scan_heap(VRelStats *vacrelstats, Relation onerel,
pfree(vtlinks);
}
elog(elevel, "Pages %u: Changed %u, reaped %u, Empty %u, New %u; \
Tup %.0f: Vac %.0f, Keep/VTL %.0f/%u, UnUsed %.0f, MinLen %lu, MaxLen %lu; \
Re-using: Free/Avail. Space %.0f/%.0f; EndEmpty/Avail. Pages %u/%u.\n\t%s",
elog(elevel, "Pages %u: Changed %u, reaped %u, Empty %u, New %u; "
"Tup %.0f: Vac %.0f, Keep/VTL %.0f/%u, UnUsed %.0f, MinLen %lu, "
"MaxLen %lu; Re-using: Free/Avail. Space %.0f/%.0f; "
"EndEmpty/Avail. Pages %u/%u.\n\t%s",
nblocks, changed_pages, vacuum_pages->num_pages, empty_pages,
new_pages, num_tuples, tups_vacuumed,
nkeep, vacrelstats->num_vtlinks,
......@@ -2597,8 +2598,8 @@ scan_index(Relation indrel, double num_tuples)
{
if (stats->num_index_tuples > num_tuples ||
!vac_is_partial_index(indrel))
elog(WARNING, "Index %s: NUMBER OF INDEX' TUPLES (%.0f) IS NOT THE SAME AS HEAP' (%.0f).\
\n\tRecreate the index.",
elog(WARNING, "Index %s: NUMBER OF INDEX' TUPLES (%.0f) IS NOT THE SAME AS HEAP' (%.0f)."
"\n\tRecreate the index.",
RelationGetRelationName(indrel),
stats->num_index_tuples, num_tuples);
}
......@@ -2651,8 +2652,8 @@ vacuum_index(VacPageList vacpagelist, Relation indrel,
{
if (stats->num_index_tuples > num_tuples + keep_tuples ||
!vac_is_partial_index(indrel))
elog(WARNING, "Index %s: NUMBER OF INDEX' TUPLES (%.0f) IS NOT THE SAME AS HEAP' (%.0f).\
\n\tRecreate the index.",
elog(WARNING, "Index %s: NUMBER OF INDEX' TUPLES (%.0f) IS NOT THE SAME AS HEAP' (%.0f)."
"\n\tRecreate the index.",
RelationGetRelationName(indrel),
stats->num_index_tuples, num_tuples);
}
......@@ -2731,35 +2732,32 @@ vac_update_fsm(Relation onerel, VacPageList fraged_pages,
{
int nPages = fraged_pages->num_pages;
int i;
BlockNumber *pages;
Size *spaceAvail;
PageFreeSpaceInfo *pageSpaces;
/* +1 to avoid palloc(0) */
pages = (BlockNumber *) palloc((nPages + 1) * sizeof(BlockNumber));
spaceAvail = (Size *) palloc((nPages + 1) * sizeof(Size));
pageSpaces = (PageFreeSpaceInfo *)
palloc((nPages + 1) * sizeof(PageFreeSpaceInfo));
for (i = 0; i < nPages; i++)
{
pages[i] = fraged_pages->pagedesc[i]->blkno;
spaceAvail[i] = fraged_pages->pagedesc[i]->free;
pageSpaces[i].blkno = fraged_pages->pagedesc[i]->blkno;
pageSpaces[i].avail = fraged_pages->pagedesc[i]->free;
/*
* fraged_pages may contain entries for pages that we later
* decided to truncate from the relation; don't enter them into
* the map!
* the free space map!
*/
if (pages[i] >= rel_pages)
if (pageSpaces[i].blkno >= rel_pages)
{
nPages = i;
break;
}
}
MultiRecordFreeSpace(&onerel->rd_node,
0, MaxBlockNumber,
nPages, pages, spaceAvail);
pfree(pages);
pfree(spaceAvail);
MultiRecordFreeSpace(&onerel->rd_node, 0, nPages, pageSpaces);
pfree(pageSpaces);
}
/* Copy a VacPage structure */
......
......@@ -31,7 +31,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/vacuumlazy.c,v 1.19 2002/09/04 20:31:17 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/vacuumlazy.c,v 1.20 2002/09/20 19:56:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -87,9 +87,8 @@ typedef struct LVRelStats
/* We use a simple array until it fills up, then convert to heap */
bool fs_is_heap; /* are we using heap organization? */
int num_free_pages; /* current # of entries */
int max_free_pages; /* # slots allocated in arrays */
BlockNumber *free_pages; /* array or heap of block numbers */
Size *free_spaceavail; /* array or heap of available space */
int max_free_pages; /* # slots allocated in array */
PageFreeSpaceInfo *free_pages; /* array or heap of blkno/avail */
} LVRelStats;
......@@ -119,6 +118,7 @@ static bool lazy_tid_reaped(ItemPointer itemptr, void *state);
static bool dummy_tid_reaped(ItemPointer itemptr, void *state);
static void lazy_update_fsm(Relation onerel, LVRelStats *vacrelstats);
static int vac_cmp_itemptr(const void *left, const void *right);
static int vac_cmp_page_spaces(const void *left, const void *right);
/*
......@@ -432,8 +432,7 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
lazy_scan_index(Irel[i], vacrelstats);
}
elog(elevel, "Pages %u: Changed %u, Empty %u; \
Tup %.0f: Vac %.0f, Keep %.0f, UnUsed %.0f.\n\tTotal %s",
elog(elevel, "Pages %u: Changed %u, Empty %u; Tup %.0f: Vac %.0f, Keep %.0f, UnUsed %.0f.\n\tTotal %s",
nblocks, changed_pages, empty_pages,
num_tuples, tups_vacuumed, nkeep, nunused,
vac_show_rusage(&ru0));
......@@ -662,8 +661,7 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
{
BlockNumber old_rel_pages = vacrelstats->rel_pages;
BlockNumber new_rel_pages;
BlockNumber *pages;
Size *spaceavail;
PageFreeSpaceInfo *pageSpaces;
int n;
int i,
j;
......@@ -736,20 +734,20 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
* Drop free-space info for removed blocks; these must not get entered
* into the FSM!
*/
pages = vacrelstats->free_pages;
spaceavail = vacrelstats->free_spaceavail;
pageSpaces = vacrelstats->free_pages;
n = vacrelstats->num_free_pages;
j = 0;
for (i = 0; i < n; i++)
{
if (pages[i] < new_rel_pages)
if (pageSpaces[i].blkno < new_rel_pages)
{
pages[j] = pages[i];
spaceavail[j] = spaceavail[i];
pageSpaces[j] = pageSpaces[i];
j++;
}
}
vacrelstats->num_free_pages = j;
/* We destroyed the heap ordering, so mark array unordered */
vacrelstats->fs_is_heap = false;
/*
* We keep the exclusive lock until commit (perhaps not necessary)?
......@@ -913,10 +911,8 @@ lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
vacrelstats->fs_is_heap = false;
vacrelstats->num_free_pages = 0;
vacrelstats->max_free_pages = maxpages;
vacrelstats->free_pages = (BlockNumber *)
palloc(maxpages * sizeof(BlockNumber));
vacrelstats->free_spaceavail = (Size *)
palloc(maxpages * sizeof(Size));
vacrelstats->free_pages = (PageFreeSpaceInfo *)
palloc(maxpages * sizeof(PageFreeSpaceInfo));
}
/*
......@@ -946,8 +942,7 @@ lazy_record_free_space(LVRelStats *vacrelstats,
BlockNumber page,
Size avail)
{
BlockNumber *pages;
Size *spaceavail;
PageFreeSpaceInfo *pageSpaces;
int n;
/* Ignore pages with little free space */
......@@ -955,15 +950,14 @@ lazy_record_free_space(LVRelStats *vacrelstats,
return;
/* Copy pointers to local variables for notational simplicity */
pages = vacrelstats->free_pages;
spaceavail = vacrelstats->free_spaceavail;
pageSpaces = vacrelstats->free_pages;
n = vacrelstats->max_free_pages;
/* If we haven't filled the array yet, just keep adding entries */
if (vacrelstats->num_free_pages < n)
{
pages[vacrelstats->num_free_pages] = page;
spaceavail[vacrelstats->num_free_pages] = avail;
pageSpaces[vacrelstats->num_free_pages].blkno = page;
pageSpaces[vacrelstats->num_free_pages].avail = avail;
vacrelstats->num_free_pages++;
return;
}
......@@ -971,7 +965,7 @@ lazy_record_free_space(LVRelStats *vacrelstats,
/*----------
* The rest of this routine works with "heap" organization of the
* free space arrays, wherein we maintain the heap property
* spaceavail[(j-1) div 2] <= spaceavail[j] for 0 < j < n.
* avail[(j-1) div 2] <= avail[j] for 0 < j < n.
* In particular, the zero'th element always has the smallest available
* space and can be discarded to make room for a new page with more space.
* See Knuth's discussion of heap-based priority queues, sec 5.2.3;
......@@ -991,8 +985,8 @@ lazy_record_free_space(LVRelStats *vacrelstats,
while (--l >= 0)
{
BlockNumber R = pages[l];
Size K = spaceavail[l];
BlockNumber R = pageSpaces[l].blkno;
Size K = pageSpaces[l].avail;
int i; /* i is where the "hole" is */
i = l;
......@@ -1002,23 +996,22 @@ lazy_record_free_space(LVRelStats *vacrelstats,
if (j >= n)
break;
if (j + 1 < n && spaceavail[j] > spaceavail[j + 1])
if (j + 1 < n && pageSpaces[j].avail > pageSpaces[j + 1].avail)
j++;
if (K <= spaceavail[j])
if (K <= pageSpaces[j].avail)
break;
pages[i] = pages[j];
spaceavail[i] = spaceavail[j];
pageSpaces[i] = pageSpaces[j];
i = j;
}
pages[i] = R;
spaceavail[i] = K;
pageSpaces[i].blkno = R;
pageSpaces[i].avail = K;
}
vacrelstats->fs_is_heap = true;
}
/* If new page has more than zero'th entry, insert it into heap */
if (avail > spaceavail[0])
if (avail > pageSpaces[0].avail)
{
/*
* Notionally, we replace the zero'th entry with the new data, and
......@@ -1034,16 +1027,15 @@ lazy_record_free_space(LVRelStats *vacrelstats,
if (j >= n)
break;
if (j + 1 < n && spaceavail[j] > spaceavail[j + 1])
if (j + 1 < n && pageSpaces[j].avail > pageSpaces[j + 1].avail)
j++;
if (avail <= spaceavail[j])
if (avail <= pageSpaces[j].avail)
break;
pages[i] = pages[j];
spaceavail[i] = spaceavail[j];
pageSpaces[i] = pageSpaces[j];
i = j;
}
pages[i] = page;
spaceavail[i] = avail;
pageSpaces[i].blkno = page;
pageSpaces[i].avail = avail;
}
}
......@@ -1085,16 +1077,17 @@ dummy_tid_reaped(ItemPointer itemptr, void *state)
static void
lazy_update_fsm(Relation onerel, LVRelStats *vacrelstats)
{
PageFreeSpaceInfo *pageSpaces = vacrelstats->free_pages;
int nPages = vacrelstats->num_free_pages;
/*
* Since MultiRecordFreeSpace doesn't currently impose any
* restrictions on the ordering of the input, we can just pass it the
* arrays as-is, whether they are in heap or linear order.
* Sort data into order, as required by MultiRecordFreeSpace.
*/
MultiRecordFreeSpace(&onerel->rd_node,
0, MaxBlockNumber,
vacrelstats->num_free_pages,
vacrelstats->free_pages,
vacrelstats->free_spaceavail);
if (nPages > 1)
qsort(pageSpaces, nPages, sizeof(PageFreeSpaceInfo),
vac_cmp_page_spaces);
MultiRecordFreeSpace(&onerel->rd_node, 0, nPages, pageSpaces);
}
/*
......@@ -1126,3 +1119,16 @@ vac_cmp_itemptr(const void *left, const void *right)
return 0;
}
static int
vac_cmp_page_spaces(const void *left, const void *right)
{
PageFreeSpaceInfo *linfo = (PageFreeSpaceInfo *) left;
PageFreeSpaceInfo *rinfo = (PageFreeSpaceInfo *) right;
if (linfo->blkno < rinfo->blkno)
return -1;
else if (linfo->blkno > rinfo->blkno)
return 1;
return 0;
}
......@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/freespace/freespace.c,v 1.13 2002/09/04 20:31:25 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/freespace/freespace.c,v 1.14 2002/09/20 19:56:01 tgl Exp $
*
*
* NOTES:
......@@ -99,6 +99,7 @@ struct FSMRelation
* about */
int numChunks; /* number of FSMChunks allocated to rel */
FSMChunk *relChunks; /* linked list of page info chunks */
FSMChunk *lastChunk; /* last chunk in linked list */
};
/*
......@@ -142,6 +143,7 @@ static bool lookup_fsm_page_entry(FSMRelation *fsmrel, BlockNumber page,
static bool insert_fsm_page_entry(FSMRelation *fsmrel,
BlockNumber page, Size spaceAvail,
FSMChunk *chunk, int chunkRelIndex);
static bool append_fsm_chunk(FSMRelation *fsmrel);
static bool push_fsm_page_entry(BlockNumber page, Size spaceAvail,
FSMChunk *chunk, int chunkRelIndex);
static void delete_fsm_page_entry(FSMRelation *fsmrel, FSMChunk *chunk,
......@@ -359,21 +361,20 @@ RecordAndGetPageWithFreeSpace(RelFileNode *rel,
* MultiRecordFreeSpace - record available-space info about multiple pages
* of a relation in one call.
*
* First, if minPage <= maxPage, the FSM must discard any entries it has for
* pages in that page number range (inclusive). This allows obsolete info
* to be discarded. Second, if nPages > 0, record the page numbers and free
* space amounts in the given arrays. As with RecordFreeSpace, the FSM is at
* liberty to discard some of the information. However, it *must* discard
* previously stored info in the minPage..maxPage range (for example, this
* case is used to remove info about deleted pages during relation truncation).
* First, the FSM must discard any entries it has for pages >= minPage.
* This allows obsolete info to be discarded (for example, it is used when
* truncating a relation). Any entries before minPage should be kept.
*
* Second, if nPages > 0, record the page numbers and free space amounts in
* the given pageSpaces[] array. As with RecordFreeSpace, the FSM is at
* liberty to discard some of this information. The pageSpaces[] array must
* be sorted in order by blkno, and may not contain entries before minPage.
*/
void
MultiRecordFreeSpace(RelFileNode *rel,
BlockNumber minPage,
BlockNumber maxPage,
int nPages,
BlockNumber *pages,
Size *spaceAvail)
PageFreeSpaceInfo *pageSpaces)
{
FSMRelation *fsmrel;
int i;
......@@ -383,59 +384,64 @@ MultiRecordFreeSpace(RelFileNode *rel,
if (fsmrel)
{
/*
* Remove entries in specified range
* Remove entries >= minPage
*/
if (minPage <= maxPage)
FSMChunk *chunk;
int chunkRelIndex;
/* Use lookup to locate first entry >= minPage */
lookup_fsm_page_entry(fsmrel, minPage, &chunk, &chunkRelIndex);
/* Set free space to 0 for each page >= minPage */
while (chunk)
{
FSMChunk *chunk;
int chunkRelIndex;
bool done;
/* Use lookup to locate first entry >= minPage */
lookup_fsm_page_entry(fsmrel, minPage, &chunk, &chunkRelIndex);
/* Set free space to 0 for each page within range */
done = false;
while (chunk && !done)
{
int numPages = chunk->numPages;
int numPages = chunk->numPages;
for (; chunkRelIndex < numPages; chunkRelIndex++)
{
if (chunk->pages[chunkRelIndex] > maxPage)
{
done = true;
break;
}
chunk->bytes[chunkRelIndex] = 0;
}
chunk = chunk->next;
chunkRelIndex = 0;
}
/* Now compact out the zeroed entries */
compact_fsm_page_list(fsmrel);
for (i = chunkRelIndex; i < numPages; i++)
chunk->bytes[i] = 0;
chunk = chunk->next;
chunkRelIndex = 0;
}
/* Now compact out the zeroed entries, along with any other junk */
compact_fsm_page_list(fsmrel);
/*
* Add new entries, if appropriate.
*
* XXX we could probably be smarter about this than doing it
* completely separately for each one. FIXME later.
*
* One thing we can do is short-circuit the process entirely if a
* page (a) has too little free space to be recorded, and (b) is
* within the minPage..maxPage range --- then we deleted any old
* entry above, and we aren't going to make a new one. This is
* particularly useful since in most cases, all the passed pages
* will in fact be in the minPage..maxPage range.
* This can be much cheaper than a full fsm_record_free_space()
* call because we know we are appending to the end of the relation.
*/
for (i = 0; i < nPages; i++)
{
BlockNumber page = pages[i];
Size avail = spaceAvail[i];
BlockNumber page = pageSpaces[i].blkno;
Size avail = pageSpaces[i].avail;
FSMChunk *chunk;
/* Check caller provides sorted data */
if (i > 0 ? (page <= pageSpaces[i-1].blkno) : (page < minPage))
elog(ERROR, "MultiRecordFreeSpace: data not in page order");
/* Ignore pages too small to fit */
if (avail < fsmrel->threshold)
continue;
/* Get another chunk if needed */
/* We may need to loop if acquire_fsm_free_space() fails */
while ((chunk = fsmrel->lastChunk) == NULL ||
chunk->numPages >= CHUNKPAGES)
{
if (!append_fsm_chunk(fsmrel))
acquire_fsm_free_space();
}
/* Recheck in case threshold was raised by acquire */
if (avail < fsmrel->threshold)
continue;
if (avail >= fsmrel->threshold ||
page < minPage || page > maxPage)
fsm_record_free_space(fsmrel, page, avail);
/* Okay to store */
chunk->pages[chunk->numPages] = page;
chunk->bytes[chunk->numPages] = (ItemLength) avail;
chunk->numPages++;
fsmrel->numPages++;
}
}
LWLockRelease(FreeSpaceLock);
......@@ -538,6 +544,7 @@ create_fsm_rel(RelFileNode *rel)
fsmrel->numPages = 0;
fsmrel->numChunks = 0;
fsmrel->relChunks = NULL;
fsmrel->lastChunk = NULL;
/* Discard lowest-priority existing rel, if we are over limit */
if (FreeSpaceMap->numRels >= MaxFSMRelations)
delete_fsm_rel(FreeSpaceMap->relListTail);
......@@ -847,29 +854,12 @@ insert_fsm_page_entry(FSMRelation *fsmrel, BlockNumber page, Size spaceAvail,
if (fsmrel->numPages >= fsmrel->numChunks * CHUNKPAGES)
{
/* No free space within chunk list, so need another chunk */
FSMChunk *newChunk;
if ((newChunk = FreeSpaceMap->freeChunks) == NULL)
if (!append_fsm_chunk(fsmrel))
return false; /* can't do it */
FreeSpaceMap->freeChunks = newChunk->next;
FreeSpaceMap->numFreeChunks--;
newChunk->next = NULL;
newChunk->numPages = 0;
if (fsmrel->relChunks == NULL)
fsmrel->relChunks = newChunk;
else
{
FSMChunk *priorChunk = fsmrel->relChunks;
while (priorChunk->next != NULL)
priorChunk = priorChunk->next;
priorChunk->next = newChunk;
}
fsmrel->numChunks++;
if (chunk == NULL)
{
/* Original search found that new page belongs at end */
chunk = newChunk;
chunk = fsmrel->lastChunk;
chunkRelIndex = 0;
}
}
......@@ -900,6 +890,38 @@ insert_fsm_page_entry(FSMRelation *fsmrel, BlockNumber page, Size spaceAvail,
}
}
/*
* Add one chunk to a FSMRelation's chunk list, if possible.
*
* Returns TRUE if successful, FALSE if no space available. Note that on
* success, the new chunk is easily accessible via fsmrel->lastChunk.
*/
static bool
append_fsm_chunk(FSMRelation *fsmrel)
{
FSMChunk *newChunk;
/* Remove a chunk from the freelist */
if ((newChunk = FreeSpaceMap->freeChunks) == NULL)
return false; /* can't do it */
FreeSpaceMap->freeChunks = newChunk->next;
FreeSpaceMap->numFreeChunks--;
/* Initialize chunk to empty */
newChunk->next = NULL;
newChunk->numPages = 0;
/* Link it into FSMRelation */
if (fsmrel->relChunks == NULL)
fsmrel->relChunks = newChunk;
else
fsmrel->lastChunk->next = newChunk;
fsmrel->lastChunk = newChunk;
fsmrel->numChunks++;
return true;
}
/*
* Auxiliary routine for insert_fsm_page_entry: try to push entries to the
* right to insert at chunk/chunkRelIndex. Return TRUE if successful.
......@@ -1016,6 +1038,7 @@ compact_fsm_page_list(FSMRelation *fsmrel)
fsmrel->numPages = 0;
fsmrel->numChunks = 0;
fsmrel->relChunks = NULL;
fsmrel->lastChunk = NULL;
free_chunk_chain(dstChunk);
}
else
......@@ -1026,6 +1049,7 @@ compact_fsm_page_list(FSMRelation *fsmrel)
dstChunk->numPages = dstIndex;
free_chunk_chain(dstChunk->next);
dstChunk->next = NULL;
fsmrel->lastChunk = dstChunk;
}
}
......
......@@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/smgr/smgr.c,v 1.60 2002/09/04 20:31:26 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/smgr/smgr.c,v 1.61 2002/09/20 19:56:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -410,9 +410,7 @@ smgrtruncate(int16 which, Relation reln, BlockNumber nblocks)
* for the about-to-be-deleted blocks. We want to be sure it
* won't return bogus block numbers later on.
*/
MultiRecordFreeSpace(&reln->rd_node,
nblocks, MaxBlockNumber,
0, NULL, NULL);
MultiRecordFreeSpace(&reln->rd_node, nblocks, 0, NULL);
newblks = (*(smgrsw[which].smgr_truncate)) (reln, nblocks);
if (newblks == InvalidBlockNumber)
......
......@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: freespace.h,v 1.7 2002/06/20 20:29:52 momjian Exp $
* $Id: freespace.h,v 1.8 2002/09/20 19:56:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -18,6 +18,16 @@
#include "storage/relfilenode.h"
/*
* exported types
*/
typedef struct PageFreeSpaceInfo
{
BlockNumber blkno; /* which page in relation */
Size avail; /* space available on this page */
} PageFreeSpaceInfo;
extern int MaxFSMRelations;
extern int MaxFSMPages;
......@@ -37,10 +47,8 @@ extern BlockNumber RecordAndGetPageWithFreeSpace(RelFileNode *rel,
Size spaceNeeded);
extern void MultiRecordFreeSpace(RelFileNode *rel,
BlockNumber minPage,
BlockNumber maxPage,
int nPages,
BlockNumber *pages,
Size *spaceAvail);
PageFreeSpaceInfo *pageSpaces);
extern void FreeSpaceMapForgetRel(RelFileNode *rel);
extern void FreeSpaceMapForgetDatabase(Oid dbid);
......
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