Re: Autovacuum / full vacuum

От: Michael Riess
Тема: Re: Autovacuum / full vacuum
Дата: ,
Msg-id: dqj121$3jm$1@news.hub.org
(см: обсуждение, исходный текст)
Ответ на: Re: Autovacuum / full vacuum  (Andrew Sullivan)
Ответы: Re: Autovacuum / full vacuum  (Andrew Sullivan)
Список: pgsql-performance

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Autovacuum / full vacuum  (Michael Riess, )
 Re: Autovacuum / full vacuum  (Christopher Kings-Lynne, )
  Re: Autovacuum / full vacuum  (Michael Riess, )
   Re: Autovacuum / full vacuum  (Michael Stone, )
   Re: Autovacuum / full vacuum  ("Matthew T. O'Connor", )
    Re: Autovacuum / full vacuum  (Markus Schaber, )
    Re: Autovacuum / full vacuum  (Michael Riess, )
     Re: Autovacuum / full vacuum  (Tom Lane, )
     Re: Autovacuum / full vacuum  (Markus Schaber, )
    Re: Autovacuum / full vacuum  (Andrew Sullivan, )
  Re: Autovacuum / full vacuum  (Pandurangan R S, )
 Re: Autovacuum / full vacuum  (Alvaro Herrera <-ip.org>, )
 Re: Autovacuum / full vacuum  (Christopher Browne, )
  Re: Autovacuum / full vacuum  (Michael Riess, )
   Re: Autovacuum / full vacuum  (Andrew Sullivan, )
 Re: Autovacuum / full vacuum  ("Larry Rosenman", )
 Re: Autovacuum / full vacuum  (Christopher Browne, )
  Re: Autovacuum / full vacuum  (Michael Riess, )
   Re: Autovacuum / full vacuum  (Michael Stone, )
   Re: Autovacuum / full vacuum  (Andrew Sullivan, )
    Re: Autovacuum / full vacuum  (Scott Marlowe, )
     Re: Autovacuum / full vacuum  (Andrew Sullivan, )
      Re: Autovacuum / full vacuum  (Scott Marlowe, )
   Re: Autovacuum / full vacuum  (hubert depesz lubaczewski, )
   Re: Autovacuum / full vacuum  ("Jim C. Nasby", )
    Re: Autovacuum / full vacuum  (Michael Riess, )
     Re: Autovacuum / full vacuum  ("Jim C. Nasby", )
 Re: Autovacuum / full vacuum  (Andrew Sullivan, )
  Re: Autovacuum / full vacuum  (Michael Riess, )
   Re: Autovacuum / full vacuum  (Andrew Sullivan, )
 Re: Autovacuum / full vacuum  (Tom Lane, )
 Re: Autovacuum / full vacuum  (Chris Browne, )
  Re: Autovacuum / full vacuum  (Alvaro Herrera <-ip.org>, )
  Re: Autovacuum / full vacuum  (Andrew Sullivan, )
 Re: Autovacuum / full vacuum  (Chris Browne, )
  Re: Autovacuum / full vacuum  (Tom Lane, )
 Re: Autovacuum / full vacuum  ("Mindaugas", )
  Re: Autovacuum / full vacuum  (Alvaro Herrera <-ip.org>, )
 Re: Autovacuum / full vacuum  (Chris Browne, )
  Re: Autovacuum / full vacuum (off-topic?)  (Michael Crozier, )
   Re: Autovacuum / full vacuum (off-topic?)  ("Jim C. Nasby", )
    Re: Autovacuum / full vacuum (off-topic?)  (Michael Crozier, )
     Re: Autovacuum / full vacuum (off-topic?)  ("Jim C. Nasby", )
    Re: Autovacuum / full vacuum (off-topic?)  (Mark Kirkwood, )
     Re: Autovacuum / full vacuum (off-topic?)  (Bruce Momjian, )
     Re: Autovacuum / full vacuum (off-topic?)  ("Jim C. Nasby", )
      Re: Autovacuum / full vacuum (off-topic?)  ("Joshua D. Drake", )
       Re: Autovacuum / full vacuum (off-topic?)  ("Jim C. Nasby", )
        Re: Autovacuum / full vacuum (off-topic?)  ("Joshua D. Drake", )
         Re: Autovacuum / full vacuum (off-topic?)  ("Jim C. Nasby", )
 Re: Autovacuum / full vacuum (off-topic?)  (Chris Browne, )
  Re: Autovacuum / full vacuum (off-topic?)  (Michael Crozier, )
 Re: Autovacuum / full vacuum (off-topic?)  (<>, )
  Re: Autovacuum / full vacuum (off-topic?)  ("Jim C. Nasby", )

Hi,

>> hi,
>>
>> I'm curious as to why autovacuum is not designed to do full vacuum. I
>
> Because nothing that runs automatically should ever take an exclusive
> lock on the entire database, which is what VACUUM FULL does.

I thought that vacuum full only locks the table which it currently
operates on? I'm pretty sure that once a table has been vacuumed, it can
be accessed without any restrictions while the vacuum process works on
the next table.

>
>> activity. Increasing the FSM so that even during these bursts most space
>>  would be reused would mean to reduce the available memory for all
>> other database tasks.
>
> I don't believe the hit is enough that you should even notice it.
> You'd have to post some pretty incredible use cases to show that the
> tiny loss of memory to FSM is worth (a) an exclusive lock and (b) the
> loss of efficiency you get from having some preallocated pages in
> tables.

I have 5000 tables and a workstation with 1 GB RAM which hosts an Apache
   Web Server, Tomcat Servlet Container and PostgreSQL. RAM is not
something that I have plenty of ... and the hardware is fixed and cannot
be changed.




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