Re: VACUUM ANALYZE blocking both reads and writes to a table

От: Peter Schuller
Тема: Re: VACUUM ANALYZE blocking both reads and writes to a table
Дата: ,
Msg-id: 20080630153435.GA15756@hyperion.scode.org
(см: обсуждение, исходный текст)
Ответ на: Re: VACUUM ANALYZE blocking both reads and writes to a table  (Alvaro Herrera)
Список: pgsql-performance

Скрыть дерево обсуждения

VACUUM ANALYZE blocking both reads and writes to a table  (Peter Schuller, )
 Re: VACUUM ANALYZE blocking both reads and writes to a table  (Alvaro Herrera, )
  Re: VACUUM ANALYZE blocking both reads and writes to a table  (Peter Schuller, )
  Re: VACUUM ANALYZE blocking both reads and writes to a table  (Peter Schuller, )
   Re: VACUUM ANALYZE blocking both reads and writes to a table  (Alvaro Herrera, )
    Re: VACUUM ANALYZE blocking both reads and writes to a table  (Tom Lane, )
     Re: VACUUM ANALYZE blocking both reads and writes to a table  (Alvaro Herrera, )
      Re: VACUUM ANALYZE blocking both reads and writes to a table  (Peter Schuller, )
    Re: VACUUM ANALYZE blocking both reads and writes to a table  (Alvaro Herrera, )

Hello,

> No.  VACUUM takes an exclusive lock at the end of the operation to
> truncate empty pages.  (If it cannot get the lock then it'll just skip
> this step.)  In 8.2.4 there was a bug that caused it to sleep
> according to vacuum_delay during the scan to identify possibly empty
> pages.  This was fixed in 8.2.5:

[snip revision log]

Thank you very much! This does indeed seem to be the likely
culprit. Will try to either upgrade, or if not possible in time for
the next occurance, confirm that this is what is happening based on
pg_locks.

Thanks again for the very informative response.

--
/ Peter Schuller

PGP userID: 0xE9758B7D or 'Peter Schuller <>'
Key retrieval: Send an E-Mail to 
E-Mail:  Web: http://www.scode.org


Вложения

В списке pgsql-performance по дате сообщения:

От: Mark Roberts
Дата:
Сообщение: Re: Does max size of varchar influence index size
От: John Beaver
Дата:
Сообщение: Re: sequence scan problem