Re: Memory usage of auto-vacuum

From: Gael Le Mignot
Subject: Re: Memory usage of auto-vacuum
Date: ,
Msg-id: plop87mxgjjygn.fsf@aoskar.kilobug.org
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In response to: Memory usage of auto-vacuum  (Gael Le Mignot)
List: pgsql-performance

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Memory usage of auto-vacuum  (Gael Le Mignot, )
 Re: Memory usage of auto-vacuum  (Craig Ringer, )
  Re: Memory usage of auto-vacuum  (Gael Le Mignot, )
 Re: Memory usage of auto-vacuum  (Guillaume Lelarge, )
  Re: Memory usage of auto-vacuum  (Gael Le Mignot, )
   Re: Memory usage of auto-vacuum  (Guillaume Lelarge, )
    Re: Memory usage of auto-vacuum  (Gael Le Mignot, )
     Re: Memory usage of auto-vacuum  (Guillaume Lelarge, )
      Re: Memory usage of auto-vacuum  (Gael Le Mignot, )
       Re: Memory usage of auto-vacuum  (Tom Lane, )
        Re: Memory usage of auto-vacuum  (Gael Le Mignot, )
   Re: Memory usage of auto-vacuum  (Craig Ringer, )
 Re: Memory usage of auto-vacuum  (Gael Le Mignot, )

Hello,

Here is an update on my problem :

- the problem was caused by "VACUUM ANALYZE", but by a plain "VACUUM" ;

- it was exactly the same with manual and automatic "VACUUM ANALYZE" ;

- it was caused by a GIN index on a tsvector, using a very high (10000)
  statistics target.

Setting back the statistics to 1000  reduced the amount of RAM used to a
very reasonable amount.

The value of 10000 is indeed  not very realistic, but I think that would
deserve some mention on the  documentation, if possible with an estimate
of  the maximal memory  usage for  a given  statistics target  and table
size.

Do  you think  it's a  good idea,  and if  so, if  that estimate  can be
reasonably made ?

Regards,

--
Gaël Le Mignot - 
Pilot Systems - 9, rue Desargues - 75011 Paris
Tel : +33 1 44 53 05 55 - www.pilotsystems.net
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