Re: Autovacuum / full vacuum

От: Andrew Sullivan
Тема: Re: Autovacuum / full vacuum
Дата: ,
Msg-id: 20060117145649.GE21092@phlogiston.dyndns.org
(см: обсуждение, исходный текст)
Ответ на: Autovacuum / full vacuum  (Michael Riess)
Ответы: Re: Autovacuum / full vacuum  (Michael Riess)
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", )

On Tue, Jan 17, 2006 at 11:18:59AM +0100, Michael Riess wrote:
> 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.

> 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.

A

--
Andrew Sullivan  | 
The fact that technology doesn't work is no bar to success in the marketplace.
        --Philip Greenspun


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