Re: stats collector suddenly causing lots of IO

От: Tom Lane
Тема: Re: stats collector suddenly causing lots of IO
Дата: ,
Msg-id: 25790.1271370070@sss.pgh.pa.us
(см: обсуждение, исходный текст)
Ответ на: stats collector suddenly causing lots of IO  (Chris)
Список: pgsql-performance

Скрыть дерево обсуждения

stats collector suddenly causing lots of IO  (Chris, )
 Re: stats collector suddenly causing lots of IO  (Cédric Villemain, )
 Re: stats collector suddenly causing lots of IO  (Alvaro Herrera, )
 Re: stats collector suddenly causing lots of IO  (Tom Lane, )
 Re: stats collector suddenly causing lots of IO  (Josh Kupershmidt, )
  Re: stats collector suddenly causing lots of IO  (Tom Lane, )
   Re: stats collector suddenly causing lots of IO  (Josh Kupershmidt, )
    Re: stats collector suddenly causing lots of IO  (Tom Lane, )
     Re: stats collector suddenly causing lots of IO  (Josh Kupershmidt, )
      Re: stats collector suddenly causing lots of IO  (Tom Lane, )
       Re: stats collector suddenly causing lots of IO  (Scott Carey, )
        Re: stats collector suddenly causing lots of IO  (Scott Carey, )
       Re: stats collector suddenly causing lots of IO  (Josh Kupershmidt, )
        Re: stats collector suddenly causing lots of IO  (Greg Smith, )
         Re: stats collector suddenly causing lots of IO  (Josh Kupershmidt, )
          Re: stats collector suddenly causing lots of IO  (Greg Smith, )
          Re: stats collector suddenly causing lots of IO  (Tom Lane, )
           Re: stats collector suddenly causing lots of IO  (Josh Kupershmidt, )
 Re: stats collector suddenly causing lots of IO  (Tom Lane, )
 Re: stats collector suddenly causing lots of IO  (Tom Lane, )
  Re: stats collector suddenly causing lots of IO  (Tom Lane, )

Chris <> writes:
> I have a lot of centos servers which are running postgres.  Postgres isn't used
> that heavily on any of them, but lately, the stats collector process keeps
> causing tons of IO load.  It seems to happen only on servers with centos 5.
> The versions of postgres that are running are:

> 8.1.18
> 8.2.6
> 8.3.1
> 8.3.5
> 8.3.6
> 8.3.7
> 8.3.8
> 8.3.9
> 8.4.2
> 8.4.3

Do these different server versions really all show the problem to the
same extent?  I'd expect 8.4.x in particular to be cheaper than the
older branches.  Are their pgstat.stat files all of similar sizes?
(Note that 8.4.x keeps pgstat.stat under $PGDATA/pg_stat_tmp/ whereas
in earlier versions it was under $PGDATA/global/.)

If your applications create/use/drop a lot of tables (perhaps temp
tables) then bloat of the pgstat.stat file is to be expected, but
it should get cleaned up by vacuum (including autovacuum).  What is
your vacuuming policy on these servers ... do you use autovacuum?

            regards, tom lane


В списке pgsql-performance по дате сообщения:

От: Dave Crooke
Дата:
Сообщение: SOLVED: Re: HELP: How to tame the 8.3.x JDBC driver with a biq guery result set
От: Віталій Тимчишин
Дата:
Сообщение: Planner not using column limit specified for one column for another column equal to first