Re: pg_autovacuum seems to be a neat freak and cleans way - Mailing list pgsql-general

From Bruce Momjian
Subject Re: pg_autovacuum seems to be a neat freak and cleans way
Date
Msg-id 200405190216.i4J2Ghd23845@candle.pha.pa.us
Whole thread Raw
In response to pg_autovacuum seems to be a neat freak and cleans way too much  (Brian Hirt <bhirt@mobygames.com>)
Responses Re: pg_autovacuum seems to be a neat freak and cleans way
List pgsql-general
Brian Hirt wrote:
> I've having a strange issue with pg_autovacuum.   I have a table with
> about 4 million rows in 20,000 pages.   autovacuum likes to vacuum
> and/or analyze  it every 45 minutes or so, but it probably doesn't have
> more that a few hundred rows changed every few hours.   when i run
> autovacuum with -d3 it says
>
> [2004-05-18 07:04:26 PM]   table name:
> basement_nightly."public"."search_words4"
> [2004-05-18 07:04:26 PM]      relid: 396238832;   relisshared: 0
> [2004-05-18 07:04:26 PM]      reltuples: 4;  relpages: 20013
> [2004-05-18 07:04:26 PM]      curr_analyze_count:  0; cur_delete_count:
>    0
> [2004-05-18 07:04:26 PM]      ins_at_last_analyze: 0;
> del_at_last_vacuum: 0
> [2004-05-18 07:04:26 PM]      insert_threshold:    504;
> delete_threshold    1008
>
> reltuples: 4 seems wrong.  I would expect a table with 4m rows and 20k
> pages to have more than 4 tuples.   I think this is why the insert
> threshhold is all messed up -- which is why it gets analyzed way too
> frequently.
>
> this happens with other big tables too.   the autovacuum is from 7.4.2,
> some information is below.

Oh, 7.4.2.  I know we have some known bug and are waiting on a patch for
it.

Matthew, we need those fixes for pg_autovacuum soon.

--
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