Header And Logo
|
#include "postgres.h"#include <math.h>#include "access/genam.h"#include "access/heapam.h"#include "access/heapam_xlog.h"#include "access/htup_details.h"#include "access/multixact.h"#include "access/transam.h"#include "access/visibilitymap.h"#include "catalog/storage.h"#include "commands/dbcommands.h"#include "commands/vacuum.h"#include "miscadmin.h"#include "pgstat.h"#include "portability/instr_time.h"#include "postmaster/autovacuum.h"#include "storage/bufmgr.h"#include "storage/freespace.h"#include "storage/lmgr.h"#include "utils/lsyscache.h"#include "utils/memutils.h"#include "utils/pg_rusage.h"#include "utils/timestamp.h"#include "utils/tqual.h"
Go to the source code of this file.
| #define LAZY_ALLOC_TUPLES MaxHeapTuplesPerPage |
Definition at line 90 of file vacuumlazy.c.
Referenced by lazy_space_alloc().
| #define REL_TRUNCATE_FRACTION 16 |
Definition at line 72 of file vacuumlazy.c.
Referenced by lazy_vacuum_rel().
| #define REL_TRUNCATE_MINIMUM 1000 |
Definition at line 71 of file vacuumlazy.c.
Referenced by lazy_vacuum_rel().
| #define SKIP_PAGES_THRESHOLD ((BlockNumber) 32) |
Definition at line 96 of file vacuumlazy.c.
Referenced by lazy_scan_heap().
| #define VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL 20 |
Definition at line 81 of file vacuumlazy.c.
Referenced by count_nondeletable_pages().
| #define VACUUM_TRUNCATE_LOCK_TIMEOUT 5000 |
Definition at line 83 of file vacuumlazy.c.
Referenced by lazy_truncate_heap().
| #define VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL 50 |
Definition at line 82 of file vacuumlazy.c.
Referenced by lazy_truncate_heap().
| typedef struct LVRelStats LVRelStats |
| static BlockNumber count_nondeletable_pages | ( | Relation | onerel, | |
| LVRelStats * | vacrelstats | |||
| ) | [static] |
Definition at line 1444 of file vacuumlazy.c.
References AccessExclusiveLock, buf, BUFFER_LOCK_SHARE, BufferGetPage, CHECK_FOR_INTERRUPTS, elevel, ereport, errmsg(), FirstOffsetNumber, INSTR_TIME_GET_MICROSEC, INSTR_TIME_SET_CURRENT, INSTR_TIME_SUBTRACT, ItemIdIsUsed, LVRelStats::lock_waiter_detected, LockBuffer(), LockHasWaitersRelation(), MAIN_FORKNUM, LVRelStats::nonempty_pages, OffsetNumberNext, PageGetItemId, PageGetMaxOffsetNumber, PageIsEmpty, PageIsNew, RBM_NORMAL, ReadBufferExtended(), LVRelStats::rel_pages, RelationGetRelationName, UnlockReleaseBuffer(), and VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL.
Referenced by lazy_truncate_heap().
{
BlockNumber blkno;
instr_time starttime;
/* Initialize the starttime if we check for conflicting lock requests */
INSTR_TIME_SET_CURRENT(starttime);
/* Strange coding of loop control is needed because blkno is unsigned */
blkno = vacrelstats->rel_pages;
while (blkno > vacrelstats->nonempty_pages)
{
Buffer buf;
Page page;
OffsetNumber offnum,
maxoff;
bool hastup;
/*
* Check if another process requests a lock on our relation. We are
* holding an AccessExclusiveLock here, so they will be waiting. We
* only do this once per VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL, and we
* only check if that interval has elapsed once every 32 blocks to
* keep the number of system calls and actual shared lock table
* lookups to a minimum.
*/
if ((blkno % 32) == 0)
{
instr_time currenttime;
instr_time elapsed;
INSTR_TIME_SET_CURRENT(currenttime);
elapsed = currenttime;
INSTR_TIME_SUBTRACT(elapsed, starttime);
if ((INSTR_TIME_GET_MICROSEC(elapsed) / 1000)
>= VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL)
{
if (LockHasWaitersRelation(onerel, AccessExclusiveLock))
{
ereport(elevel,
(errmsg("\"%s\": suspending truncate due to conflicting lock request",
RelationGetRelationName(onerel))));
vacrelstats->lock_waiter_detected = true;
return blkno;
}
starttime = currenttime;
}
}
/*
* We don't insert a vacuum delay point here, because we have an
* exclusive lock on the table which we want to hold for as short a
* time as possible. We still need to check for interrupts however.
*/
CHECK_FOR_INTERRUPTS();
blkno--;
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
RBM_NORMAL, vac_strategy);
/* In this phase we only need shared access to the buffer */
LockBuffer(buf, BUFFER_LOCK_SHARE);
page = BufferGetPage(buf);
if (PageIsNew(page) || PageIsEmpty(page))
{
/* PageIsNew probably shouldn't happen... */
UnlockReleaseBuffer(buf);
continue;
}
hastup = false;
maxoff = PageGetMaxOffsetNumber(page);
for (offnum = FirstOffsetNumber;
offnum <= maxoff;
offnum = OffsetNumberNext(offnum))
{
ItemId itemid;
itemid = PageGetItemId(page, offnum);
/*
* Note: any non-unused item should be taken as a reason to keep
* this page. We formerly thought that DEAD tuples could be
* thrown away, but that's not so, because we'd not have cleaned
* out their index entries.
*/
if (ItemIdIsUsed(itemid))
{
hastup = true;
break; /* can stop scanning */
}
} /* scan along page */
UnlockReleaseBuffer(buf);
/* Done scanning if we found a tuple here */
if (hastup)
return blkno + 1;
}
/*
* If we fall out of the loop, all the previously-thought-to-be-empty
* pages still are; we need not bother to look at the last known-nonempty
* page.
*/
return vacrelstats->nonempty_pages;
}
| static bool heap_page_is_all_visible | ( | Buffer | buf, | |
| TransactionId * | visibility_cutoff_xid | |||
| ) | [static] |
Definition at line 1667 of file vacuumlazy.c.
References Assert, BufferGetBlockNumber(), BufferGetPage, elog, ERROR, FirstOffsetNumber, HEAP_XMIN_COMMITTED, HEAPTUPLE_DEAD, HEAPTUPLE_DELETE_IN_PROGRESS, HEAPTUPLE_INSERT_IN_PROGRESS, HEAPTUPLE_LIVE, HEAPTUPLE_RECENTLY_DEAD, HeapTupleHeaderGetXmin, HeapTupleSatisfiesVacuum(), ItemIdIsDead, ItemIdIsNormal, ItemIdIsRedirected, ItemIdIsUsed, ItemPointerSet, OffsetNumberNext, OldestXmin, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, TransactionIdFollows(), and TransactionIdPrecedes().
Referenced by lazy_vacuum_page().
{
Page page = BufferGetPage(buf);
OffsetNumber offnum,
maxoff;
bool all_visible = true;
*visibility_cutoff_xid = InvalidTransactionId;
/*
* This is a stripped down version of the line pointer scan in
* lazy_scan_heap(). So if you change anything here, also check that
* code.
*/
maxoff = PageGetMaxOffsetNumber(page);
for (offnum = FirstOffsetNumber;
offnum <= maxoff && all_visible;
offnum = OffsetNumberNext(offnum))
{
ItemId itemid;
HeapTupleData tuple;
itemid = PageGetItemId(page, offnum);
/* Unused or redirect line pointers are of no interest */
if (!ItemIdIsUsed(itemid) || ItemIdIsRedirected(itemid))
continue;
ItemPointerSet(&(tuple.t_self), BufferGetBlockNumber(buf), offnum);
/*
* Dead line pointers can have index pointers pointing to them. So they
* can't be treated as visible
*/
if (ItemIdIsDead(itemid))
{
all_visible = false;
break;
}
Assert(ItemIdIsNormal(itemid));
tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
switch (HeapTupleSatisfiesVacuum(tuple.t_data, OldestXmin, buf))
{
case HEAPTUPLE_LIVE:
{
TransactionId xmin;
/* Check comments in lazy_scan_heap. */
if (!(tuple.t_data->t_infomask & HEAP_XMIN_COMMITTED))
{
all_visible = false;
break;
}
/*
* The inserter definitely committed. But is it old
* enough that everyone sees it as committed?
*/
xmin = HeapTupleHeaderGetXmin(tuple.t_data);
if (!TransactionIdPrecedes(xmin, OldestXmin))
{
all_visible = false;
break;
}
/* Track newest xmin on page. */
if (TransactionIdFollows(xmin, *visibility_cutoff_xid))
*visibility_cutoff_xid = xmin;
}
break;
case HEAPTUPLE_DEAD:
case HEAPTUPLE_RECENTLY_DEAD:
case HEAPTUPLE_INSERT_IN_PROGRESS:
case HEAPTUPLE_DELETE_IN_PROGRESS:
all_visible = false;
break;
default:
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
break;
}
} /* scan along page */
return all_visible;
}
Definition at line 1191 of file vacuumlazy.c.
References BufferGetPage, FirstOffsetNumber, FreezeLimit, heap_tuple_needs_freeze(), ItemIdIsNormal, MultiXactFrzLimit, OffsetNumberNext, PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, PageIsEmpty, and PageIsNew.
Referenced by lazy_scan_heap().
{
Page page;
OffsetNumber offnum,
maxoff;
HeapTupleHeader tupleheader;
page = BufferGetPage(buf);
if (PageIsNew(page) || PageIsEmpty(page))
{
/* PageIsNew probably shouldn't happen... */
return false;
}
maxoff = PageGetMaxOffsetNumber(page);
for (offnum = FirstOffsetNumber;
offnum <= maxoff;
offnum = OffsetNumberNext(offnum))
{
ItemId itemid;
itemid = PageGetItemId(page, offnum);
if (!ItemIdIsNormal(itemid))
continue;
tupleheader = (HeapTupleHeader) PageGetItem(page, itemid);
if (heap_tuple_needs_freeze(tupleheader, FreezeLimit,
MultiXactFrzLimit, buf))
return true;
} /* scan along page */
return false;
}
| static void lazy_cleanup_index | ( | Relation | indrel, | |
| IndexBulkDeleteResult * | stats, | |||
| LVRelStats * | vacrelstats | |||
| ) | [static] |
Definition at line 1267 of file vacuumlazy.c.
References IndexVacuumInfo::analyze_only, elevel, ereport, errdetail(), errmsg(), IndexBulkDeleteResult::estimated_count, IndexVacuumInfo::estimated_count, IndexVacuumInfo::index, index_vacuum_cleanup(), InvalidMultiXactId, InvalidTransactionId, IndexVacuumInfo::message_level, LVRelStats::new_rel_tuples, IndexVacuumInfo::num_heap_tuples, IndexBulkDeleteResult::num_index_tuples, IndexBulkDeleteResult::num_pages, IndexBulkDeleteResult::pages_deleted, IndexBulkDeleteResult::pages_free, pfree(), pg_rusage_init(), pg_rusage_show(), LVRelStats::rel_pages, RelationGetRelationName, LVRelStats::scanned_pages, IndexVacuumInfo::strategy, IndexBulkDeleteResult::tuples_removed, and vac_update_relstats().
Referenced by lazy_scan_heap().
{
IndexVacuumInfo ivinfo;
PGRUsage ru0;
pg_rusage_init(&ru0);
ivinfo.index = indrel;
ivinfo.analyze_only = false;
ivinfo.estimated_count = (vacrelstats->scanned_pages < vacrelstats->rel_pages);
ivinfo.message_level = elevel;
ivinfo.num_heap_tuples = vacrelstats->new_rel_tuples;
ivinfo.strategy = vac_strategy;
stats = index_vacuum_cleanup(&ivinfo, stats);
if (!stats)
return;
/*
* Now update statistics in pg_class, but only if the index says the count
* is accurate.
*/
if (!stats->estimated_count)
vac_update_relstats(indrel,
stats->num_pages,
stats->num_index_tuples,
0,
false,
InvalidTransactionId,
InvalidMultiXactId);
ereport(elevel,
(errmsg("index \"%s\" now contains %.0f row versions in %u pages",
RelationGetRelationName(indrel),
stats->num_index_tuples,
stats->num_pages),
errdetail("%.0f index row versions were removed.\n"
"%u index pages have been deleted, %u are currently reusable.\n"
"%s.",
stats->tuples_removed,
stats->pages_deleted, stats->pages_free,
pg_rusage_show(&ru0))));
pfree(stats);
}
| static void lazy_record_dead_tuple | ( | LVRelStats * | vacrelstats, | |
| ItemPointer | itemptr | |||
| ) | [static] |
Definition at line 1594 of file vacuumlazy.c.
References LVRelStats::dead_tuples, LVRelStats::max_dead_tuples, and LVRelStats::num_dead_tuples.
Referenced by lazy_scan_heap().
{
/*
* The array shouldn't overflow under normal behavior, but perhaps it
* could if we are given a really small maintenance_work_mem. In that
* case, just forget the last few tuples (we'll get 'em next time).
*/
if (vacrelstats->num_dead_tuples < vacrelstats->max_dead_tuples)
{
vacrelstats->dead_tuples[vacrelstats->num_dead_tuples] = *itemptr;
vacrelstats->num_dead_tuples++;
}
}
| static void lazy_scan_heap | ( | Relation | onerel, | |
| LVRelStats * | vacrelstats, | |||
| Relation * | Irel, | |||
| int | nindexes, | |||
| bool | scan_all | |||
| ) | [static] |
Definition at line 393 of file vacuumlazy.c.
References Assert, buf, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BufferGetPage, BufferGetPageSize, BufferIsValid, ConditionalLockBufferForCleanup(), elevel, elog, ereport, errdetail(), errmsg(), ERROR, ExclusiveLock, FirstOffsetNumber, FreezeLimit, get_namespace_name(), heap_freeze_tuple(), heap_page_prune(), HEAP_XMIN_COMMITTED, HEAPTUPLE_DEAD, HEAPTUPLE_DELETE_IN_PROGRESS, HEAPTUPLE_INSERT_IN_PROGRESS, HEAPTUPLE_LIVE, HEAPTUPLE_RECENTLY_DEAD, HeapTupleGetOid, HeapTupleHeaderAdvanceLatestRemovedXid(), HeapTupleHeaderGetXmin, HeapTupleIsHeapOnly, HeapTupleIsHotUpdated, HeapTupleSatisfiesVacuum(), i, InvalidTransactionId, InvalidXLogRecPtr, ItemIdGetLength, ItemIdIsDead, ItemIdIsNormal, ItemIdIsRedirected, ItemIdIsUsed, ItemPointerSet, LVRelStats::latestRemovedXid, lazy_check_needs_freeze(), lazy_cleanup_index(), lazy_record_dead_tuple(), lazy_space_alloc(), lazy_vacuum_heap(), lazy_vacuum_index(), lazy_vacuum_page(), LockBuffer(), LockBufferForCleanup(), LockRelationForExtension(), log_heap_freeze(), MAIN_FORKNUM, MarkBufferDirty(), LVRelStats::max_dead_tuples, MaxHeapTuplesPerPage, MultiXactFrzLimit, LVRelStats::new_rel_tuples, LVRelStats::nonempty_pages, LVRelStats::num_dead_tuples, LVRelStats::num_index_scans, OffsetNumberNext, OidIsValid, OldestXmin, PageClearAllVisible, PageGetHeapFreeSpace(), PageGetItem, PageGetItemId, PageGetMaxOffsetNumber, PageInit(), PageIsAllVisible, PageIsEmpty, PageIsNew, PageSetAllVisible, PageSetLSN, palloc0(), pg_rusage_init(), pg_rusage_show(), RBM_NORMAL, RelationData::rd_rel, ReadBufferExtended(), RecordPageWithFreeSpace(), LVRelStats::rel_pages, RelationGetNamespace, RelationGetNumberOfBlocks, RelationGetRelationName, RelationNeedsWAL, ReleaseBuffer(), LVRelStats::scanned_pages, LVRelStats::scanned_tuples, SKIP_PAGES_THRESHOLD, HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_len, HeapTupleData::t_self, TransactionIdFollows(), TransactionIdPrecedes(), LVRelStats::tuples_deleted, UnlockRelationForExtension(), UnlockReleaseBuffer(), vac_estimate_reltuples(), vacuum_delay_point(), vacuum_log_cleanup_info(), visibilitymap_clear(), visibilitymap_pin(), visibilitymap_set(), visibilitymap_test(), and WARNING.
Referenced by lazy_vacuum_rel().
{
BlockNumber nblocks,
blkno;
HeapTupleData tuple;
char *relname;
BlockNumber empty_pages,
vacuumed_pages;
double num_tuples,
tups_vacuumed,
nkeep,
nunused;
IndexBulkDeleteResult **indstats;
int i;
PGRUsage ru0;
Buffer vmbuffer = InvalidBuffer;
BlockNumber next_not_all_visible_block;
bool skipping_all_visible_blocks;
pg_rusage_init(&ru0);
relname = RelationGetRelationName(onerel);
ereport(elevel,
(errmsg("vacuuming \"%s.%s\"",
get_namespace_name(RelationGetNamespace(onerel)),
relname)));
empty_pages = vacuumed_pages = 0;
num_tuples = tups_vacuumed = nkeep = nunused = 0;
indstats = (IndexBulkDeleteResult **)
palloc0(nindexes * sizeof(IndexBulkDeleteResult *));
nblocks = RelationGetNumberOfBlocks(onerel);
vacrelstats->rel_pages = nblocks;
vacrelstats->scanned_pages = 0;
vacrelstats->nonempty_pages = 0;
vacrelstats->latestRemovedXid = InvalidTransactionId;
lazy_space_alloc(vacrelstats, nblocks);
/*
* We want to skip pages that don't require vacuuming according to the
* visibility map, but only when we can skip at least SKIP_PAGES_THRESHOLD
* consecutive pages. Since we're reading sequentially, the OS should be
* doing readahead for us, so there's no gain in skipping a page now and
* then; that's likely to disable readahead and so be counterproductive.
* Also, skipping even a single page means that we can't update
* relfrozenxid, so we only want to do it if we can skip a goodly number
* of pages.
*
* Before entering the main loop, establish the invariant that
* next_not_all_visible_block is the next block number >= blkno that's not
* all-visible according to the visibility map, or nblocks if there's no
* such block. Also, we set up the skipping_all_visible_blocks flag,
* which is needed because we need hysteresis in the decision: once we've
* started skipping blocks, we may as well skip everything up to the next
* not-all-visible block.
*
* Note: if scan_all is true, we won't actually skip any pages; but we
* maintain next_not_all_visible_block anyway, so as to set up the
* all_visible_according_to_vm flag correctly for each page.
*
* Note: The value returned by visibilitymap_test could be slightly
* out-of-date, since we make this test before reading the corresponding
* heap page or locking the buffer. This is OK. If we mistakenly think
* that the page is all-visible when in fact the flag's just been cleared,
* we might fail to vacuum the page. But it's OK to skip pages when
* scan_all is not set, so no great harm done; the next vacuum will find
* them. If we make the reverse mistake and vacuum a page unnecessarily,
* it'll just be a no-op.
*/
for (next_not_all_visible_block = 0;
next_not_all_visible_block < nblocks;
next_not_all_visible_block++)
{
if (!visibilitymap_test(onerel, next_not_all_visible_block, &vmbuffer))
break;
vacuum_delay_point();
}
if (next_not_all_visible_block >= SKIP_PAGES_THRESHOLD)
skipping_all_visible_blocks = true;
else
skipping_all_visible_blocks = false;
for (blkno = 0; blkno < nblocks; blkno++)
{
Buffer buf;
Page page;
OffsetNumber offnum,
maxoff;
bool tupgone,
hastup;
int prev_dead_count;
OffsetNumber frozen[MaxOffsetNumber];
int nfrozen;
Size freespace;
bool all_visible_according_to_vm;
bool all_visible;
bool has_dead_tuples;
TransactionId visibility_cutoff_xid = InvalidTransactionId;
if (blkno == next_not_all_visible_block)
{
/* Time to advance next_not_all_visible_block */
for (next_not_all_visible_block++;
next_not_all_visible_block < nblocks;
next_not_all_visible_block++)
{
if (!visibilitymap_test(onerel, next_not_all_visible_block,
&vmbuffer))
break;
vacuum_delay_point();
}
/*
* We know we can't skip the current block. But set up
* skipping_all_visible_blocks to do the right thing at the
* following blocks.
*/
if (next_not_all_visible_block - blkno > SKIP_PAGES_THRESHOLD)
skipping_all_visible_blocks = true;
else
skipping_all_visible_blocks = false;
all_visible_according_to_vm = false;
}
else
{
/* Current block is all-visible */
if (skipping_all_visible_blocks && !scan_all)
continue;
all_visible_according_to_vm = true;
}
vacuum_delay_point();
/*
* If we are close to overrunning the available space for dead-tuple
* TIDs, pause and do a cycle of vacuuming before we tackle this page.
*/
if ((vacrelstats->max_dead_tuples - vacrelstats->num_dead_tuples) < MaxHeapTuplesPerPage &&
vacrelstats->num_dead_tuples > 0)
{
/*
* Before beginning index vacuuming, we release any pin we may
* hold on the visibility map page. This isn't necessary for
* correctness, but we do it anyway to avoid holding the pin
* across a lengthy, unrelated operation.
*/
if (BufferIsValid(vmbuffer))
{
ReleaseBuffer(vmbuffer);
vmbuffer = InvalidBuffer;
}
/* Log cleanup info before we touch indexes */
vacuum_log_cleanup_info(onerel, vacrelstats);
/* Remove index entries */
for (i = 0; i < nindexes; i++)
lazy_vacuum_index(Irel[i],
&indstats[i],
vacrelstats);
/* Remove tuples from heap */
lazy_vacuum_heap(onerel, vacrelstats);
/*
* Forget the now-vacuumed tuples, and press on, but be careful
* not to reset latestRemovedXid since we want that value to be
* valid.
*/
vacrelstats->num_dead_tuples = 0;
vacrelstats->num_index_scans++;
}
/*
* Pin the visibility map page in case we need to mark the page
* all-visible. In most cases this will be very cheap, because we'll
* already have the correct page pinned anyway. However, it's
* possible that (a) next_not_all_visible_block is covered by a
* different VM page than the current block or (b) we released our pin
* and did a cycle of index vacuuming.
*/
visibilitymap_pin(onerel, blkno, &vmbuffer);
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
RBM_NORMAL, vac_strategy);
/* We need buffer cleanup lock so that we can prune HOT chains. */
if (!ConditionalLockBufferForCleanup(buf))
{
/*
* If we're not scanning the whole relation to guard against XID
* wraparound, it's OK to skip vacuuming a page. The next vacuum
* will clean it up.
*/
if (!scan_all)
{
ReleaseBuffer(buf);
continue;
}
/*
* If this is a wraparound checking vacuum, then we read the page
* with share lock to see if any xids need to be frozen. If the
* page doesn't need attention we just skip and continue. If it
* does, we wait for cleanup lock.
*
* We could defer the lock request further by remembering the page
* and coming back to it later, or we could even register
* ourselves for multiple buffers and then service whichever one
* is received first. For now, this seems good enough.
*/
LockBuffer(buf, BUFFER_LOCK_SHARE);
if (!lazy_check_needs_freeze(buf))
{
UnlockReleaseBuffer(buf);
continue;
}
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
LockBufferForCleanup(buf);
/* drop through to normal processing */
}
vacrelstats->scanned_pages++;
page = BufferGetPage(buf);
if (PageIsNew(page))
{
/*
* An all-zeroes page could be left over if a backend extends the
* relation but crashes before initializing the page. Reclaim such
* pages for use.
*
* We have to be careful here because we could be looking at a
* page that someone has just added to the relation and not yet
* been able to initialize (see RelationGetBufferForTuple). To
* protect against that, release the buffer lock, grab the
* relation extension lock momentarily, and re-lock the buffer. If
* the page is still uninitialized by then, it must be left over
* from a crashed backend, and we can initialize it.
*
* We don't really need the relation lock when this is a new or
* temp relation, but it's probably not worth the code space to
* check that, since this surely isn't a critical path.
*
* Note: the comparable code in vacuum.c need not worry because
* it's got exclusive lock on the whole relation.
*/
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
LockRelationForExtension(onerel, ExclusiveLock);
UnlockRelationForExtension(onerel, ExclusiveLock);
LockBufferForCleanup(buf);
if (PageIsNew(page))
{
ereport(WARNING,
(errmsg("relation \"%s\" page %u is uninitialized --- fixing",
relname, blkno)));
PageInit(page, BufferGetPageSize(buf), 0);
empty_pages++;
}
freespace = PageGetHeapFreeSpace(page);
MarkBufferDirty(buf);
UnlockReleaseBuffer(buf);
RecordPageWithFreeSpace(onerel, blkno, freespace);
continue;
}
if (PageIsEmpty(page))
{
empty_pages++;
freespace = PageGetHeapFreeSpace(page);
/* empty pages are always all-visible */
if (!PageIsAllVisible(page))
{
PageSetAllVisible(page);
MarkBufferDirty(buf);
visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
vmbuffer, InvalidTransactionId);
}
UnlockReleaseBuffer(buf);
RecordPageWithFreeSpace(onerel, blkno, freespace);
continue;
}
/*
* Prune all HOT-update chains in this page.
*
* We count tuples removed by the pruning step as removed by VACUUM.
*/
tups_vacuumed += heap_page_prune(onerel, buf, OldestXmin, false,
&vacrelstats->latestRemovedXid);
/*
* Now scan the page to collect vacuumable items and check for tuples
* requiring freezing.
*/
all_visible = true;
has_dead_tuples = false;
nfrozen = 0;
hastup = false;
prev_dead_count = vacrelstats->num_dead_tuples;
maxoff = PageGetMaxOffsetNumber(page);
/*
* Note: If you change anything in the loop below, also look at
* heap_page_is_all_visible to see if that needs to be changed.
*/
for (offnum = FirstOffsetNumber;
offnum <= maxoff;
offnum = OffsetNumberNext(offnum))
{
ItemId itemid;
itemid = PageGetItemId(page, offnum);
/* Unused items require no processing, but we count 'em */
if (!ItemIdIsUsed(itemid))
{
nunused += 1;
continue;
}
/* Redirect items mustn't be touched */
if (ItemIdIsRedirected(itemid))
{
hastup = true; /* this page won't be truncatable */
continue;
}
ItemPointerSet(&(tuple.t_self), blkno, offnum);
/*
* DEAD item pointers are to be vacuumed normally; but we don't
* count them in tups_vacuumed, else we'd be double-counting (at
* least in the common case where heap_page_prune() just freed up
* a non-HOT tuple).
*/
if (ItemIdIsDead(itemid))
{
lazy_record_dead_tuple(vacrelstats, &(tuple.t_self));
all_visible = false;
continue;
}
Assert(ItemIdIsNormal(itemid));
tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
tuple.t_len = ItemIdGetLength(itemid);
tupgone = false;
switch (HeapTupleSatisfiesVacuum(tuple.t_data, OldestXmin, buf))
{
case HEAPTUPLE_DEAD:
/*
* Ordinarily, DEAD tuples would have been removed by
* heap_page_prune(), but it's possible that the tuple
* state changed since heap_page_prune() looked. In
* particular an INSERT_IN_PROGRESS tuple could have
* changed to DEAD if the inserter aborted. So this
* cannot be considered an error condition.
*
* If the tuple is HOT-updated then it must only be
* removed by a prune operation; so we keep it just as if
* it were RECENTLY_DEAD. Also, if it's a heap-only
* tuple, we choose to keep it, because it'll be a lot
* cheaper to get rid of it in the next pruning pass than
* to treat it like an indexed tuple.
*/
if (HeapTupleIsHotUpdated(&tuple) ||
HeapTupleIsHeapOnly(&tuple))
nkeep += 1;
else
tupgone = true; /* we can delete the tuple */
all_visible = false;
break;
case HEAPTUPLE_LIVE:
/* Tuple is good --- but let's do some validity checks */
if (onerel->rd_rel->relhasoids &&
!OidIsValid(HeapTupleGetOid(&tuple)))
elog(WARNING, "relation \"%s\" TID %u/%u: OID is invalid",
relname, blkno, offnum);
/*
* Is the tuple definitely visible to all transactions?
*
* NB: Like with per-tuple hint bits, we can't set the
* PD_ALL_VISIBLE flag if the inserter committed
* asynchronously. See SetHintBits for more info. Check
* that the HEAP_XMIN_COMMITTED hint bit is set because of
* that.
*/
if (all_visible)
{
TransactionId xmin;
if (!(tuple.t_data->t_infomask & HEAP_XMIN_COMMITTED))
{
all_visible = false;
break;
}
/*
* The inserter definitely committed. But is it old
* enough that everyone sees it as committed?
*/
xmin = HeapTupleHeaderGetXmin(tuple.t_data);
if (!TransactionIdPrecedes(xmin, OldestXmin))
{
all_visible = false;
break;
}
/* Track newest xmin on page. */
if (TransactionIdFollows(xmin, visibility_cutoff_xid))
visibility_cutoff_xid = xmin;
}
break;
case HEAPTUPLE_RECENTLY_DEAD:
/*
* If tuple is recently deleted then we must not remove it
* from relation.
*/
nkeep += 1;
all_visible = false;
break;
case HEAPTUPLE_INSERT_IN_PROGRESS:
/* This is an expected case during concurrent vacuum */
all_visible = false;
break;
case HEAPTUPLE_DELETE_IN_PROGRESS:
/* This is an expected case during concurrent vacuum */
all_visible = false;
break;
default:
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
break;
}
if (tupgone)
{
lazy_record_dead_tuple(vacrelstats, &(tuple.t_self));
HeapTupleHeaderAdvanceLatestRemovedXid(tuple.t_data,
&vacrelstats->latestRemovedXid);
tups_vacuumed += 1;
has_dead_tuples = true;
}
else
{
num_tuples += 1;
hastup = true;
/*
* Each non-removable tuple must be checked to see if it needs
* freezing. Note we already have exclusive buffer lock.
*/
if (heap_freeze_tuple(tuple.t_data, FreezeLimit,
MultiXactFrzLimit))
frozen[nfrozen++] = offnum;
}
} /* scan along page */
/*
* If we froze any tuples, mark the buffer dirty, and write a WAL
* record recording the changes. We must log the changes to be
* crash-safe against future truncation of CLOG.
*/
if (nfrozen > 0)
{
MarkBufferDirty(buf);
if (RelationNeedsWAL(onerel))
{
XLogRecPtr recptr;
recptr = log_heap_freeze(onerel, buf, FreezeLimit,
MultiXactFrzLimit, frozen, nfrozen);
PageSetLSN(page, recptr);
}
}
/*
* If there are no indexes then we can vacuum the page right now
* instead of doing a second scan.
*/
if (nindexes == 0 &&
vacrelstats->num_dead_tuples > 0)
{
/* Remove tuples from heap */
lazy_vacuum_page(onerel, blkno, buf, 0, vacrelstats, &vmbuffer);
/*
* Forget the now-vacuumed tuples, and press on, but be careful
* not to reset latestRemovedXid since we want that value to be
* valid.
*/
vacrelstats->num_dead_tuples = 0;
vacuumed_pages++;
}
freespace = PageGetHeapFreeSpace(page);
/* mark page all-visible, if appropriate */
if (all_visible && !all_visible_according_to_vm)
{
/*
* It should never be the case that the visibility map page is set
* while the page-level bit is clear, but the reverse is allowed
* (if checksums are not enabled). Regardless, set the both bits
* so that we get back in sync.
*
* NB: If the heap page is all-visible but the VM bit is not set,
* we don't need to dirty the heap page. However, if checksums are
* enabled, we do need to make sure that the heap page is dirtied
* before passing it to visibilitymap_set(), because it may be
* logged. Given that this situation should only happen in rare
* cases after a crash, it is not worth optimizing.
*/
PageSetAllVisible(page);
MarkBufferDirty(buf);
visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
vmbuffer, visibility_cutoff_xid);
}
/*
* As of PostgreSQL 9.2, the visibility map bit should never be set if
* the page-level bit is clear. However, it's possible that the bit
* got cleared after we checked it and before we took the buffer
* content lock, so we must recheck before jumping to the conclusion
* that something bad has happened.
*/
else if (all_visible_according_to_vm && !PageIsAllVisible(page)
&& visibilitymap_test(onerel, blkno, &vmbuffer))
{
elog(WARNING, "page is not marked all-visible but visibility map bit is set in relation \"%s\" page %u",
relname, blkno);
visibilitymap_clear(onerel, blkno, vmbuffer);
}
/*
* It's possible for the value returned by GetOldestXmin() to move
* backwards, so it's not wrong for us to see tuples that appear to
* not be visible to everyone yet, while PD_ALL_VISIBLE is already
* set. The real safe xmin value never moves backwards, but
* GetOldestXmin() is conservative and sometimes returns a value
* that's unnecessarily small, so if we see that contradiction it just
* means that the tuples that we think are not visible to everyone yet
* actually are, and the PD_ALL_VISIBLE flag is correct.
*
* There should never be dead tuples on a page with PD_ALL_VISIBLE
* set, however.
*/
else if (PageIsAllVisible(page) && has_dead_tuples)
{
elog(WARNING, "page containing dead tuples is marked as all-visible in relation \"%s\" page %u",
relname, blkno);
PageClearAllVisible(page);
MarkBufferDirty(buf);
visibilitymap_clear(onerel, blkno, vmbuffer);
}
UnlockReleaseBuffer(buf);
/* Remember the location of the last page with nonremovable tuples */
if (hastup)
vacrelstats->nonempty_pages = blkno + 1;
/*
* If we remembered any tuples for deletion, then the page will be
* visited again by lazy_vacuum_heap, which will compute and record
* its post-compaction free space. If not, then we're done with this
* page, so remember its free space as-is. (This path will always be
* taken if there are no indexes.)
*/
if (vacrelstats->num_dead_tuples == prev_dead_count)
RecordPageWithFreeSpace(onerel, blkno, freespace);
}
/* save stats for use later */
vacrelstats->scanned_tuples = num_tuples;
vacrelstats->tuples_deleted = tups_vacuumed;
/* now we can compute the new value for pg_class.reltuples */
vacrelstats->new_rel_tuples = vac_estimate_reltuples(onerel, false,
nblocks,
vacrelstats->scanned_pages,
num_tuples);
/*
* Release any remaining pin on visibility map page.
*/
if (BufferIsValid(vmbuffer))
{
ReleaseBuffer(vmbuffer);
vmbuffer = InvalidBuffer;
}
/* If any tuples need to be deleted, perform final vacuum cycle */
/* XXX put a threshold on min number of tuples here? */
if (vacrelstats->num_dead_tuples > 0)
{
/* Log cleanup info before we touch indexes */
vacuum_log_cleanup_info(onerel, vacrelstats);
/* Remove index entries */
for (i = 0; i < nindexes; i++)
lazy_vacuum_index(Irel[i],
&indstats[i],
vacrelstats);
/* Remove tuples from heap */
lazy_vacuum_heap(onerel, vacrelstats);
vacrelstats->num_index_scans++;
}
/* Do post-vacuum cleanup and statistics update for each index */
for (i = 0; i < nindexes; i++)
lazy_cleanup_index(Irel[i], indstats[i], vacrelstats);
/* If no indexes, make log report that lazy_vacuum_heap would've made */
if (vacuumed_pages)
ereport(elevel,
(errmsg("\"%s\": removed %.0f row versions in %u pages",
RelationGetRelationName(onerel),
tups_vacuumed, vacuumed_pages)));
ereport(elevel,
(errmsg("\"%s\": found %.0f removable, %.0f nonremovable row versions in %u out of %u pages",
RelationGetRelationName(onerel),
tups_vacuumed, num_tuples,
vacrelstats->scanned_pages, nblocks),
errdetail("%.0f dead row versions cannot be removed yet.\n"
"There were %.0f unused item pointers.\n"
"%u pages are entirely empty.\n"
"%s.",
nkeep,
nunused,
empty_pages,
pg_rusage_show(&ru0))));
}
| static void lazy_space_alloc | ( | LVRelStats * | vacrelstats, | |
| BlockNumber | relblocks | |||
| ) | [static] |
Definition at line 1562 of file vacuumlazy.c.
References LVRelStats::dead_tuples, LVRelStats::hasindex, LAZY_ALLOC_TUPLES, maintenance_work_mem, Max, LVRelStats::max_dead_tuples, MaxAllocSize, MaxHeapTuplesPerPage, Min, LVRelStats::num_dead_tuples, and palloc().
Referenced by lazy_scan_heap().
{
long maxtuples;
if (vacrelstats->hasindex)
{
maxtuples = (maintenance_work_mem * 1024L) / sizeof(ItemPointerData);
maxtuples = Min(maxtuples, INT_MAX);
maxtuples = Min(maxtuples, MaxAllocSize / sizeof(ItemPointerData));
/* curious coding here to ensure the multiplication can't overflow */
if ((BlockNumber) (maxtuples / LAZY_ALLOC_TUPLES) > relblocks)
maxtuples = relblocks * LAZY_ALLOC_TUPLES;
/* stay sane if small maintenance_work_mem */
maxtuples = Max(maxtuples, MaxHeapTuplesPerPage);
}
else
{
maxtuples = MaxHeapTuplesPerPage;
}
vacrelstats->num_dead_tuples = 0;
vacrelstats->max_dead_tuples = (int) maxtuples;
vacrelstats->dead_tuples = (ItemPointer)
palloc(maxtuples * sizeof(ItemPointerData));
}
| static bool lazy_tid_reaped | ( | ItemPointer | itemptr, | |
| void * | state | |||
| ) | [static] |
Definition at line 1617 of file vacuumlazy.c.
References LVRelStats::dead_tuples, NULL, and LVRelStats::num_dead_tuples.
Referenced by lazy_vacuum_index().
{
LVRelStats *vacrelstats = (LVRelStats *) state;
ItemPointer res;
res = (ItemPointer) bsearch((void *) itemptr,
(void *) vacrelstats->dead_tuples,
vacrelstats->num_dead_tuples,
sizeof(ItemPointerData),
vac_cmp_itemptr);
return (res != NULL);
}
| static void lazy_truncate_heap | ( | Relation | onerel, | |
| LVRelStats * | vacrelstats | |||
| ) | [static] |
Definition at line 1320 of file vacuumlazy.c.
References AccessExclusiveLock, CHECK_FOR_INTERRUPTS, ConditionalLockRelation(), count_nondeletable_pages(), elevel, ereport, errdetail(), errmsg(), LVRelStats::lock_waiter_detected, LVRelStats::nonempty_pages, LVRelStats::pages_removed, pg_rusage_init(), pg_rusage_show(), pg_usleep(), LVRelStats::rel_pages, RelationGetNumberOfBlocks, RelationGetRelationName, RelationTruncate(), UnlockRelation(), VACUUM_TRUNCATE_LOCK_TIMEOUT, and VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL.
Referenced by lazy_vacuum_rel().
{
BlockNumber old_rel_pages = vacrelstats->rel_pages;
BlockNumber new_rel_pages;
PGRUsage ru0;
int lock_retry;
pg_rusage_init(&ru0);
/*
* Loop until no more truncating can be done.
*/
do
{
/*
* We need full exclusive lock on the relation in order to do
* truncation. If we can't get it, give up rather than waiting --- we
* don't want to block other backends, and we don't want to deadlock
* (which is quite possible considering we already hold a lower-grade
* lock).
*/
vacrelstats->lock_waiter_detected = false;
lock_retry = 0;
while (true)
{
if (ConditionalLockRelation(onerel, AccessExclusiveLock))
break;
/*
* Check for interrupts while trying to (re-)acquire the exclusive
* lock.
*/
CHECK_FOR_INTERRUPTS();
if (++lock_retry > (VACUUM_TRUNCATE_LOCK_TIMEOUT /
VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL))
{
/*
* We failed to establish the lock in the specified number of
* retries. This means we give up truncating.
*/
vacrelstats->lock_waiter_detected = true;
ereport(elevel,
(errmsg("\"%s\": stopping truncate due to conflicting lock request",
RelationGetRelationName(onerel))));
return;
}
pg_usleep(VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL);
}
/*
* Now that we have exclusive lock, look to see if the rel has grown
* whilst we were vacuuming with non-exclusive lock. If so, give up;
* the newly added pages presumably contain non-deletable tuples.
*/
new_rel_pages = RelationGetNumberOfBlocks(onerel);
if (new_rel_pages != old_rel_pages)
{
/*
* Note: we intentionally don't update vacrelstats->rel_pages with
* the new rel size here. If we did, it would amount to assuming
* that the new pages are empty, which is unlikely. Leaving the
* numbers alone amounts to assuming that the new pages have the
* same tuple density as existing ones, which is less unlikely.
*/
UnlockRelation(onerel, AccessExclusiveLock);
return;
}
/*
* Scan backwards from the end to verify that the end pages actually
* contain no tuples. This is *necessary*, not optional, because
* other backends could have added tuples to these pages whilst we
* were vacuuming.
*/
new_rel_pages = count_nondeletable_pages(onerel, vacrelstats);
if (new_rel_pages >= old_rel_pages)
{
/* can't do anything after all */
UnlockRelation(onerel, AccessExclusiveLock);
return;
}
/*
* Okay to truncate.
*/
RelationTruncate(onerel, new_rel_pages);
/*
* We can release the exclusive lock as soon as we have truncated.
* Other backends can't safely access the relation until they have
* processed the smgr invalidation that smgrtruncate sent out ... but
* that should happen as part of standard invalidation processing once
* they acquire lock on the relation.
*/
UnlockRelation(onerel, AccessExclusiveLock);
/*
* Update statistics. Here, it *is* correct to adjust rel_pages
* without also touching reltuples, since the tuple count wasn't
* changed by the truncation.
*/
vacrelstats->pages_removed += old_rel_pages - new_rel_pages;
vacrelstats->rel_pages = new_rel_pages;
ereport(elevel,
(errmsg("\"%s\": truncated %u to %u pages",
RelationGetRelationName(onerel),
old_rel_pages, new_rel_pages),
errdetail("%s.",
pg_rusage_show(&ru0))));
old_rel_pages = new_rel_pages;
} while (new_rel_pages > vacrelstats->nonempty_pages &&
vacrelstats->lock_waiter_detected);
}
| static void lazy_vacuum_heap | ( | Relation | onerel, | |
| LVRelStats * | vacrelstats | |||
| ) | [static] |
Definition at line 1053 of file vacuumlazy.c.
References buf, BufferGetPage, BufferIsValid, ConditionalLockBufferForCleanup(), LVRelStats::dead_tuples, elevel, ereport, errdetail(), errmsg(), ItemPointerGetBlockNumber, lazy_vacuum_page(), MAIN_FORKNUM, PageGetHeapFreeSpace(), pg_rusage_init(), pg_rusage_show(), RBM_NORMAL, ReadBufferExtended(), RecordPageWithFreeSpace(), RelationGetRelationName, ReleaseBuffer(), UnlockReleaseBuffer(), and vacuum_delay_point().
Referenced by lazy_scan_heap().
{
int tupindex;
int npages;
PGRUsage ru0;
Buffer vmbuffer = InvalidBuffer;
pg_rusage_init(&ru0);
npages = 0;
tupindex = 0;
while (tupindex < vacrelstats->num_dead_tuples)
{
BlockNumber tblk;
Buffer buf;
Page page;
Size freespace;
vacuum_delay_point();
tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, tblk, RBM_NORMAL,
vac_strategy);
if (!ConditionalLockBufferForCleanup(buf))
{
ReleaseBuffer(buf);
++tupindex;
continue;
}
tupindex = lazy_vacuum_page(onerel, tblk, buf, tupindex, vacrelstats,
&vmbuffer);
/* Now that we've compacted the page, record its available space */
page = BufferGetPage(buf);
freespace = PageGetHeapFreeSpace(page);
UnlockReleaseBuffer(buf);
RecordPageWithFreeSpace(onerel, tblk, freespace);
npages++;
}
if (BufferIsValid(vmbuffer))
{
ReleaseBuffer(vmbuffer);
vmbuffer = InvalidBuffer;
}
ereport(elevel,
(errmsg("\"%s\": removed %d row versions in %d pages",
RelationGetRelationName(onerel),
tupindex, npages),
errdetail("%s.",
pg_rusage_show(&ru0))));
}
| static void lazy_vacuum_index | ( | Relation | indrel, | |
| IndexBulkDeleteResult ** | stats, | |||
| LVRelStats * | vacrelstats | |||
| ) | [static] |
Definition at line 1236 of file vacuumlazy.c.
References IndexVacuumInfo::analyze_only, elevel, ereport, errdetail(), errmsg(), IndexVacuumInfo::estimated_count, IndexVacuumInfo::index, index_bulk_delete(), lazy_tid_reaped(), IndexVacuumInfo::message_level, IndexVacuumInfo::num_heap_tuples, LVRelStats::old_rel_tuples, pg_rusage_init(), pg_rusage_show(), RelationGetRelationName, and IndexVacuumInfo::strategy.
Referenced by lazy_scan_heap().
{
IndexVacuumInfo ivinfo;
PGRUsage ru0;
pg_rusage_init(&ru0);
ivinfo.index = indrel;
ivinfo.analyze_only = false;
ivinfo.estimated_count = true;
ivinfo.message_level = elevel;
ivinfo.num_heap_tuples = vacrelstats->old_rel_tuples;
ivinfo.strategy = vac_strategy;
/* Do bulk deletion */
*stats = index_bulk_delete(&ivinfo, *stats,
lazy_tid_reaped, (void *) vacrelstats);
ereport(elevel,
(errmsg("scanned index \"%s\" to remove %d row versions",
RelationGetRelationName(indrel),
vacrelstats->num_dead_tuples),
errdetail("%s.", pg_rusage_show(&ru0))));
}
| static int lazy_vacuum_page | ( | Relation | onerel, | |
| BlockNumber | blkno, | |||
| Buffer | buffer, | |||
| int | tupindex, | |||
| LVRelStats * | vacrelstats, | |||
| Buffer * | vmbuffer | |||
| ) | [static] |
Definition at line 1119 of file vacuumlazy.c.
References Assert, BufferGetPage, BufferIsValid, LVRelStats::dead_tuples, END_CRIT_SECTION, heap_page_is_all_visible(), InvalidXLogRecPtr, ItemIdSetUnused, ItemPointerGetBlockNumber, ItemPointerGetOffsetNumber, LVRelStats::latestRemovedXid, log_heap_clean(), MarkBufferDirty(), NULL, LVRelStats::num_dead_tuples, PageGetItemId, PageRepairFragmentation(), PageSetAllVisible, PageSetLSN, RelationNeedsWAL, START_CRIT_SECTION, visibilitymap_set(), and visibilitymap_test().
Referenced by lazy_scan_heap(), and lazy_vacuum_heap().
{
Page page = BufferGetPage(buffer);
OffsetNumber unused[MaxOffsetNumber];
int uncnt = 0;
TransactionId visibility_cutoff_xid;
START_CRIT_SECTION();
for (; tupindex < vacrelstats->num_dead_tuples; tupindex++)
{
BlockNumber tblk;
OffsetNumber toff;
ItemId itemid;
tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
if (tblk != blkno)
break; /* past end of tuples for this block */
toff = ItemPointerGetOffsetNumber(&vacrelstats->dead_tuples[tupindex]);
itemid = PageGetItemId(page, toff);
ItemIdSetUnused(itemid);
unused[uncnt++] = toff;
}
PageRepairFragmentation(page);
/*
* Mark buffer dirty before we write WAL.
*
* If checksums are enabled, visibilitymap_set() may log the heap page, so
* we must mark heap buffer dirty before calling visibilitymap_set().
*/
MarkBufferDirty(buffer);
/*
* Now that we have removed the dead tuples from the page, once again check
* if the page has become all-visible.
*/
if (!visibilitymap_test(onerel, blkno, vmbuffer) &&
heap_page_is_all_visible(buffer, &visibility_cutoff_xid))
{
Assert(BufferIsValid(*vmbuffer));
PageSetAllVisible(page);
visibilitymap_set(onerel, blkno, buffer, InvalidXLogRecPtr, *vmbuffer,
visibility_cutoff_xid);
}
/* XLOG stuff */
if (RelationNeedsWAL(onerel))
{
XLogRecPtr recptr;
recptr = log_heap_clean(onerel, buffer,
NULL, 0, NULL, 0,
unused, uncnt,
vacrelstats->latestRemovedXid);
PageSetLSN(page, recptr);
}
END_CRIT_SECTION();
return tupindex;
}
| void lazy_vacuum_rel | ( | Relation | onerel, | |
| VacuumStmt * | vacstmt, | |||
| BufferAccessStrategy | bstrategy | |||
| ) |
Definition at line 168 of file vacuumlazy.c.
References elevel, ereport, errmsg(), FreeSpaceMapVacuum(), VacuumStmt::freeze_min_age, VacuumStmt::freeze_table_age, FreezeLimit, get_database_name(), get_namespace_name(), GetCurrentTimestamp(), LVRelStats::hasindex, IsAutoVacuumWorkerProcess(), lazy_scan_heap(), lazy_truncate_heap(), LVRelStats::lock_waiter_detected, LOG, Log_autovacuum_min_duration, MultiXactFrzLimit, MyDatabaseId, LVRelStats::new_rel_tuples, NoLock, LVRelStats::nonempty_pages, LVRelStats::num_index_scans, LVRelStats::old_rel_pages, LVRelStats::old_rel_tuples, OldestXmin, VacuumStmt::options, LVRelStats::pages_removed, palloc0(), pg_rusage_init(), pg_rusage_show(), pgstat_report_vacuum(), RelationData::rd_rel, LVRelStats::rel_pages, REL_TRUNCATE_FRACTION, REL_TRUNCATE_MINIMUM, RelationGetNamespace, RelationGetRelationName, RelationGetRelid, RELKIND_MATVIEW, RowExclusiveLock, LVRelStats::scanned_pages, TimestampDifference(), TimestampDifferenceExceeds(), TransactionIdPrecedesOrEquals(), LVRelStats::tuples_deleted, vac_close_indexes(), vac_open_indexes(), vac_update_relstats(), VACOPT_VERBOSE, vacuum_set_xid_limits(), VacuumPageDirty, VacuumPageHit, VacuumPageMiss, and visibilitymap_count().
Referenced by vacuum_rel().
{
LVRelStats *vacrelstats;
Relation *Irel;
int nindexes;
BlockNumber possibly_freeable;
PGRUsage ru0;
TimestampTz starttime = 0;
long secs;
int usecs;
double read_rate,
write_rate;
bool scan_all;
TransactionId freezeTableLimit;
BlockNumber new_rel_pages;
double new_rel_tuples;
BlockNumber new_rel_allvisible;
TransactionId new_frozen_xid;
MultiXactId new_min_multi;
/* measure elapsed time iff autovacuum logging requires it */
if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
{
pg_rusage_init(&ru0);
starttime = GetCurrentTimestamp();
}
if (vacstmt->options & VACOPT_VERBOSE)
elevel = INFO;
else
elevel = DEBUG2;
vac_strategy = bstrategy;
vacuum_set_xid_limits(vacstmt->freeze_min_age, vacstmt->freeze_table_age,
onerel->rd_rel->relisshared,
&OldestXmin, &FreezeLimit, &freezeTableLimit,
&MultiXactFrzLimit);
scan_all = TransactionIdPrecedesOrEquals(onerel->rd_rel->relfrozenxid,
freezeTableLimit);
vacrelstats = (LVRelStats *) palloc0(sizeof(LVRelStats));
vacrelstats->old_rel_pages = onerel->rd_rel->relpages;
vacrelstats->old_rel_tuples = onerel->rd_rel->reltuples;
vacrelstats->num_index_scans = 0;
vacrelstats->pages_removed = 0;
vacrelstats->lock_waiter_detected = false;
/* Open all indexes of the relation */
vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &Irel);
vacrelstats->hasindex = (nindexes > 0);
/* Do the vacuuming */
lazy_scan_heap(onerel, vacrelstats, Irel, nindexes, scan_all);
/* Done with indexes */
vac_close_indexes(nindexes, Irel, NoLock);
/*
* Optionally truncate the relation.
*
* Don't even think about it unless we have a shot at releasing a goodly
* number of pages. Otherwise, the time taken isn't worth it.
*
* Leave a populated materialized view with at least one page.
*/
if (onerel->rd_rel->relkind == RELKIND_MATVIEW &&
vacrelstats->nonempty_pages == 0)
vacrelstats->nonempty_pages = 1;
possibly_freeable = vacrelstats->rel_pages - vacrelstats->nonempty_pages;
if (possibly_freeable > 0 &&
(possibly_freeable >= REL_TRUNCATE_MINIMUM ||
possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION))
lazy_truncate_heap(onerel, vacrelstats);
/* Vacuum the Free Space Map */
FreeSpaceMapVacuum(onerel);
/*
* Update statistics in pg_class.
*
* A corner case here is that if we scanned no pages at all because every
* page is all-visible, we should not update relpages/reltuples, because
* we have no new information to contribute. In particular this keeps us
* from replacing relpages=reltuples=0 (which means "unknown tuple
* density") with nonzero relpages and reltuples=0 (which means "zero
* tuple density") unless there's some actual evidence for the latter.
*
* We do update relallvisible even in the corner case, since if the table
* is all-visible we'd definitely like to know that. But clamp the value
* to be not more than what we're setting relpages to.
*
* Also, don't change relfrozenxid if we skipped any pages, since then we
* don't know for certain that all tuples have a newer xmin.
*/
new_rel_pages = vacrelstats->rel_pages;
new_rel_tuples = vacrelstats->new_rel_tuples;
if (vacrelstats->scanned_pages == 0 && new_rel_pages > 0)
{
new_rel_pages = vacrelstats->old_rel_pages;
new_rel_tuples = vacrelstats->old_rel_tuples;
}
new_rel_allvisible = visibilitymap_count(onerel);
if (new_rel_allvisible > new_rel_pages)
new_rel_allvisible = new_rel_pages;
new_frozen_xid = FreezeLimit;
if (vacrelstats->scanned_pages < vacrelstats->rel_pages)
new_frozen_xid = InvalidTransactionId;
new_min_multi = MultiXactFrzLimit;
if (vacrelstats->scanned_pages < vacrelstats->rel_pages)
new_min_multi = InvalidMultiXactId;
vac_update_relstats(onerel,
new_rel_pages,
new_rel_tuples,
new_rel_allvisible,
vacrelstats->hasindex,
new_frozen_xid,
new_min_multi);
/* report results to the stats collector, too */
pgstat_report_vacuum(RelationGetRelid(onerel),
onerel->rd_rel->relisshared,
new_rel_tuples);
/* and log the action if appropriate */
if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
{
TimestampTz endtime = GetCurrentTimestamp();
if (Log_autovacuum_min_duration == 0 ||
TimestampDifferenceExceeds(starttime, endtime,
Log_autovacuum_min_duration))
{
TimestampDifference(starttime, endtime, &secs, &usecs);
read_rate = 0;
write_rate = 0;
if ((secs > 0) || (usecs > 0))
{
read_rate = (double) BLCKSZ *VacuumPageMiss / (1024 * 1024) /
(secs + usecs / 1000000.0);
write_rate = (double) BLCKSZ *VacuumPageDirty / (1024 * 1024) /
(secs + usecs / 1000000.0);
}
ereport(LOG,
(errmsg("automatic vacuum of table \"%s.%s.%s\": index scans: %d\n"
"pages: %d removed, %d remain\n"
"tuples: %.0f removed, %.0f remain\n"
"buffer usage: %d hits, %d misses, %d dirtied\n"
"avg read rate: %.3f MB/s, avg write rate: %.3f MB/s\n"
"system usage: %s",
get_database_name(MyDatabaseId),
get_namespace_name(RelationGetNamespace(onerel)),
RelationGetRelationName(onerel),
vacrelstats->num_index_scans,
vacrelstats->pages_removed,
vacrelstats->rel_pages,
vacrelstats->tuples_deleted,
vacrelstats->new_rel_tuples,
VacuumPageHit,
VacuumPageMiss,
VacuumPageDirty,
read_rate, write_rate,
pg_rusage_show(&ru0))));
}
}
}
| static int vac_cmp_itemptr | ( | const void * | left, | |
| const void * | right | |||
| ) | [static] |
Definition at line 1635 of file vacuumlazy.c.
References ItemPointerGetBlockNumber, and ItemPointerGetOffsetNumber.
{
BlockNumber lblk,
rblk;
OffsetNumber loff,
roff;
lblk = ItemPointerGetBlockNumber((ItemPointer) left);
rblk = ItemPointerGetBlockNumber((ItemPointer) right);
if (lblk < rblk)
return -1;
if (lblk > rblk)
return 1;
loff = ItemPointerGetOffsetNumber((ItemPointer) left);
roff = ItemPointerGetOffsetNumber((ItemPointer) right);
if (loff < roff)
return -1;
if (loff > roff)
return 1;
return 0;
}
| static void vacuum_log_cleanup_info | ( | Relation | rel, | |
| LVRelStats * | vacrelstats | |||
| ) | [static] |
Definition at line 360 of file vacuumlazy.c.
References LVRelStats::latestRemovedXid, log_heap_cleanup_info(), RelationData::rd_node, RelationNeedsWAL, TransactionIdIsValid, and XLogIsNeeded.
Referenced by lazy_scan_heap().
{
/*
* Skip this for relations for which no WAL is to be written, or if we're
* not trying to support archive recovery.
*/
if (!RelationNeedsWAL(rel) || !XLogIsNeeded())
return;
/*
* No need to write the record at all unless it contains a valid value
*/
if (TransactionIdIsValid(vacrelstats->latestRemovedXid))
(void) log_heap_cleanup_info(rel->rd_node, vacrelstats->latestRemovedXid);
}
int elevel = -1 [static] |
Definition at line 124 of file vacuumlazy.c.
Referenced by analyze_rel(), copy_heap_data(), count_nondeletable_pages(), errfinish(), lazy_cleanup_index(), lazy_scan_heap(), lazy_truncate_heap(), lazy_vacuum_heap(), lazy_vacuum_index(), lazy_vacuum_rel(), load_libraries(), RestoreArchivedFile(), and set_config_sourcefile().
TransactionId FreezeLimit [static] |
Definition at line 127 of file vacuumlazy.c.
Referenced by lazy_check_needs_freeze(), lazy_scan_heap(), and lazy_vacuum_rel().
MultiXactId MultiXactFrzLimit [static] |
Definition at line 128 of file vacuumlazy.c.
Referenced by copy_heap_data(), lazy_check_needs_freeze(), lazy_scan_heap(), and lazy_vacuum_rel().
TransactionId OldestXmin [static] |
Definition at line 126 of file vacuumlazy.c.
Referenced by acquire_sample_rows(), copy_heap_data(), heap_page_is_all_visible(), IndexBuildHeapScan(), lazy_scan_heap(), and lazy_vacuum_rel().
BufferAccessStrategy vac_strategy [static] |
Definition at line 130 of file vacuumlazy.c.
1.7.1