database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-15 19:21:59 +03:00
Code Activity

Fix full-table-vacuum request mechanism for MultiXactIds

Browse Source 
While autovacuum dutifully launched anti-multixact-wraparound vacuums
when the multixact "age" was reached, the vacuum code was not aware that
it needed to make them be full table vacuums.  As the resulting
partial-table vacuums aren't capable of actually increasing relminmxid,
autovacuum continued to launch anti-wraparound vacuums that didn't have
the intended effect, until age of relfrozenxid caused the vacuum to
finally be a full table one via vacuum_freeze_table_age.

To fix, introduce logic for multixacts similar to that for plain
TransactionIds, using the same GUCs.

Backpatch to 9.3, where permanent MultiXactIds were introduced.

Andres Freund, some cleanup by Álvaro
This commit is contained in:
Alvaro Herrera
2013-11-28 16:52:54 -03:00
parent d9484ab5f3
commit f5f92bdc44
6 changed files with 87 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
src/backend/commands/vacuumlazy.c
View File

@ -180,7 +180,8 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
write_rate;
bool scan_all; /* should we scan all pages? */
bool scanned_all; /* did we actually scan all pages? */
TransactionId freezeTableLimit;
TransactionId xidFullScanLimit;
MultiXactId mxactFullScanLimit;
BlockNumber new_rel_pages;
double new_rel_tuples;
BlockNumber new_rel_allvisible;
@ -203,10 +204,19 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
vacuum_set_xid_limits(vacstmt->freeze_min_age, vacstmt->freeze_table_age,
onerel->rd_rel->relisshared,
&OldestXmin, &FreezeLimit, &freezeTableLimit,
&MultiXactCutoff);
&OldestXmin, &FreezeLimit, &xidFullScanLimit,
&MultiXactCutoff, &mxactFullScanLimit);
/*
* We request a full scan if either the table's frozen Xid is now older
* than or equal to the requested Xid full-table scan limit; or if the
* table's minimum MultiXactId is older than or equal to the requested mxid
* full-table scan limit.
*/
scan_all = TransactionIdPrecedesOrEquals(onerel->rd_rel->relfrozenxid,
freezeTableLimit);
xidFullScanLimit);
scan_all |= MultiXactIdPrecedesOrEquals(onerel->rd_rel->relminmxid,
mxactFullScanLimit);
vacrelstats = (LVRelStats *) palloc0(sizeof(LVRelStats));