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-rw-r--r--src/backend/commands/vacuumlazy.c65
1 files changed, 49 insertions, 16 deletions
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 264cb437786..cc6a2a15a53 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -31,7 +31,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.72 2006/07/03 22:45:38 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.73 2006/07/10 16:20:50 alvherre Exp $
*
*-------------------------------------------------------------------------
*/
@@ -42,6 +42,7 @@
#include "access/genam.h"
#include "access/heapam.h"
#include "access/xlog.h"
+#include "catalog/catalog.h"
#include "commands/vacuum.h"
#include "miscadmin.h"
#include "pgstat.h"
@@ -72,6 +73,7 @@ typedef struct LVRelStats
double tuples_deleted;
BlockNumber nonempty_pages; /* actually, last nonempty page + 1 */
Size threshold; /* minimum interesting free space */
+ TransactionId minxid; /* minimum Xid present anywhere in table */
/* List of TIDs of tuples we intend to delete */
/* NB: this list is ordered by TID address */
int num_dead_tuples; /* current # of entries */
@@ -88,13 +90,11 @@ typedef struct LVRelStats
static int elevel = -1;
-static TransactionId OldestXmin;
-static TransactionId FreezeLimit;
-
/* non-export function prototypes */
static void lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
- Relation *Irel, int nindexes);
+ Relation *Irel, int nindexes, TransactionId FreezeLimit,
+ TransactionId OldestXmin);
static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats);
static void lazy_vacuum_index(Relation indrel,
IndexBulkDeleteResult **stats,
@@ -104,9 +104,10 @@ static void lazy_cleanup_index(Relation indrel,
LVRelStats *vacrelstats);
static int lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
int tupindex, LVRelStats *vacrelstats);
-static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats);
+static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats,
+ TransactionId OldestXmin);
static BlockNumber count_nondeletable_pages(Relation onerel,
- LVRelStats *vacrelstats);
+ LVRelStats *vacrelstats, TransactionId OldestXmin);
static void lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks);
static void lazy_record_dead_tuple(LVRelStats *vacrelstats,
ItemPointer itemptr);
@@ -122,7 +123,8 @@ static int vac_cmp_page_spaces(const void *left, const void *right);
* lazy_vacuum_rel() -- perform LAZY VACUUM for one heap relation
*
* This routine vacuums a single heap, cleans out its indexes, and
- * updates its num_pages and num_tuples statistics.
+ * updates its relpages and reltuples statistics, as well as the
+ * relminxid and relvacuumxid information.
*
* At entry, we have already established a transaction and opened
* and locked the relation.
@@ -135,6 +137,8 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt)
int nindexes;
bool hasindex;
BlockNumber possibly_freeable;
+ TransactionId OldestXmin,
+ FreezeLimit;
if (vacstmt->verbose)
elevel = INFO;
@@ -150,12 +154,23 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt)
/* XXX should we scale it up or down? Adjust vacuum.c too, if so */
vacrelstats->threshold = GetAvgFSMRequestSize(&onerel->rd_node);
+ /*
+ * Set initial minimum Xid, which will be updated if a smaller Xid is found
+ * in the relation by lazy_scan_heap.
+ *
+ * We use RecentXmin here (the minimum Xid that belongs to a transaction
+ * that is still open according to our snapshot), because it is the
+ * earliest transaction that could concurrently insert new tuples in the
+ * table.
+ */
+ vacrelstats->minxid = RecentXmin;
+
/* Open all indexes of the relation */
vac_open_indexes(onerel, ShareUpdateExclusiveLock, &nindexes, &Irel);
hasindex = (nindexes > 0);
/* Do the vacuuming */
- lazy_scan_heap(onerel, vacrelstats, Irel, nindexes);
+ lazy_scan_heap(onerel, vacrelstats, Irel, nindexes, FreezeLimit, OldestXmin);
/* Done with indexes */
vac_close_indexes(nindexes, Irel, NoLock);
@@ -169,7 +184,7 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt)
possibly_freeable = vacrelstats->rel_pages - vacrelstats->nonempty_pages;
if (possibly_freeable >= REL_TRUNCATE_MINIMUM ||
possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION)
- lazy_truncate_heap(onerel, vacrelstats);
+ lazy_truncate_heap(onerel, vacrelstats, OldestXmin);
/* Update shared free space map with final free space info */
lazy_update_fsm(onerel, vacrelstats);
@@ -178,7 +193,8 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt)
vac_update_relstats(RelationGetRelid(onerel),
vacrelstats->rel_pages,
vacrelstats->rel_tuples,
- hasindex);
+ hasindex,
+ vacrelstats->minxid, OldestXmin);
/* report results to the stats collector, too */
pgstat_report_vacuum(RelationGetRelid(onerel), onerel->rd_rel->relisshared,
@@ -193,10 +209,14 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt)
* and pages with free space, and calculates statistics on the number
* of live tuples in the heap. When done, or when we run low on space
* for dead-tuple TIDs, invoke vacuuming of indexes and heap.
+ *
+ * It also updates the minimum Xid found anywhere on the table in
+ * vacrelstats->minxid, for later storing it in pg_class.relminxid.
*/
static void
lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
- Relation *Irel, int nindexes)
+ Relation *Irel, int nindexes, TransactionId FreezeLimit,
+ TransactionId OldestXmin)
{
BlockNumber nblocks,
blkno;
@@ -406,8 +426,19 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
}
else
{
+ TransactionId min;
+
num_tuples += 1;
hastup = true;
+
+ /*
+ * If the tuple is alive, we consider it for the "minxid"
+ * calculations.
+ */
+ min = vactuple_get_minxid(&tuple);
+ if (TransactionIdIsValid(min) &&
+ TransactionIdPrecedes(min, vacrelstats->minxid))
+ vacrelstats->minxid = min;
}
} /* scan along page */
@@ -670,7 +701,7 @@ lazy_cleanup_index(Relation indrel,
vac_update_relstats(RelationGetRelid(indrel),
stats->num_pages,
stats->num_index_tuples,
- false);
+ false, InvalidTransactionId, InvalidTransactionId);
ereport(elevel,
(errmsg("index \"%s\" now contains %.0f row versions in %u pages",
@@ -691,7 +722,8 @@ lazy_cleanup_index(Relation indrel,
* lazy_truncate_heap - try to truncate off any empty pages at the end
*/
static void
-lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
+lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats,
+ TransactionId OldestXmin)
{
BlockNumber old_rel_pages = vacrelstats->rel_pages;
BlockNumber new_rel_pages;
@@ -732,7 +764,7 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
* because other backends could have added tuples to these pages whilst we
* were vacuuming.
*/
- new_rel_pages = count_nondeletable_pages(onerel, vacrelstats);
+ new_rel_pages = count_nondeletable_pages(onerel, vacrelstats, OldestXmin);
if (new_rel_pages >= old_rel_pages)
{
@@ -787,7 +819,8 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
* Returns number of nondeletable pages (last nonempty page + 1).
*/
static BlockNumber
-count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats)
+count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats,
+ TransactionId OldestXmin)
{
BlockNumber blkno;
HeapTupleData tuple;
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-25 04:35:55 +0000