From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Vincent de Phily <vincent(dot)dephily(at)mobile-devices(dot)fr> |
Cc: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, pgsql-general General <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: Speeding up an in-progress wraparound-preventing vacuum |
Date: | 2014-12-09 21:56:39 |
Message-ID: | 25318.1418162199@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
Vincent de Phily <vincent(dot)dephily(at)mobile-devices(dot)fr> writes:
> It reads about 8G of the table (often doing a similar number of writes, but
> not always), then starts reading the pkey index and the second index (only 2
> indexes on this table), reading both of them fully (some writes as well, but
> not as many as for the table), which takes around 8h.
> And the cycle apparently repeats: process a few more GB of the table, then go
> reprocess both indexes fully. A rough estimate is that it spends ~6x more time
> (re)processing the indexes as it does processing the table (looking at data
> size alone the ratio would be 41x, but the indexes go faster). I'm probably
> lucky to only have two indexes on this table.
> Is that the expected behaviour ?
Yes. It can only remember so many dead tuples at a time, and it has
to go clean the indexes when the dead-TIDs buffer fills up. You could
increase maintenance_work_mem to increase the size of that buffer.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | FarjadFarid(ChkNet) | 2014-12-09 22:00:27 | Re: List of shorthand casts |
Previous Message | FarjadFarid(ChkNet) | 2014-12-09 21:54:15 | Re: List of shorthand casts |