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1 | | -<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.76 2007/07/18 03:39:01 momjian Exp $ --> |
| 1 | +<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.77 2007/07/23 17:22:00 alvherre Exp $ --> |
2 | 2 |
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3 | 3 | <chapter id="maintenance"> |
4 | 4 | <title>Routine Database Maintenance Tasks</title> |
@@ -496,16 +496,16 @@ HINT: Stop the postmaster and use a standalone backend to VACUUM in "mydb". |
496 | 496 | </para> |
497 | 497 |
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498 | 498 | <para> |
499 | | -There is a limit of<xref linkend="guc-autovacuum-max-workers">worker |
500 | | -processes thatmay be running at any time, so if the <command>VACUUM</> |
501 | | -and <command>ANALYZE</> work to do takes too long to run, the deadline may |
502 | | -be failed to meet for other databases. Also, if a particular database |
503 | | -takes a long time to process, more than oneworkermay be processing it |
504 | | -simultaneously. The workers are smart enough to avoid repeating work that |
505 | | -other workers have done, so this is normally not a problem. Notethatthe |
506 | | -number of running workers does not count towards the<xref |
507 | | - linkend="guc-max-connections"> nor the <xref |
508 | | - linkend="guc-superuser-reserved-connections"> limits. |
| 499 | +The<xref linkend="guc-autovacuum-max-workers">setting limits how many |
| 500 | +workersmay be running at any time. If several large tables all become |
| 501 | +eligible for vacuuming in a short amount of time, all autovacuum workers |
| 502 | +may end up vacuuming those tables for a very long time. This would result |
| 503 | +in other tables and databases not being vacuumed until aworkerbecame |
| 504 | +available. There is also not a limit on how many workers might be in a |
| 505 | +single database, but workers do try and avoid repeating workthathas |
| 506 | +already been done by other workers. Note that thenumber of running |
| 507 | +workers does not count towards the <xreflinkend="guc-max-connections"> nor |
| 508 | +the <xreflinkend="guc-superuser-reserved-connections"> limits. |
509 | 509 | </para> |
510 | 510 |
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511 | 511 | <para> |
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