Re: PostgreSQL as a local in-memory cache

От: Bruce Momjian
Тема: Re: PostgreSQL as a local in-memory cache
Дата: ,
Msg-id: 201006291719.o5THJeK29759@momjian.us
(см: обсуждение, исходный текст)
Ответ на: Re: PostgreSQL as a local in-memory cache  (Robert Haas)
Ответы: Re: PostgreSQL as a local in-memory cache  (Tom Lane)
Список: pgsql-performance

Скрыть дерево обсуждения

PostgreSQL as a local in-memory cache  ("", )
 Re: PostgreSQL as a local in-memory cache  ("", )
  Re: PostgreSQL as a local in-memory cache  (Josh Berkus, )
   Re: PostgreSQL as a local in-memory cache  ("Pierre C", )
   Re: PostgreSQL as a local in-memory cache  (Dimitri Fontaine, )
    Re: PostgreSQL as a local in-memory cache  (Tom Lane, )
     Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
      Re: PostgreSQL as a local in-memory cache  (Pavel Stehule, )
       Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
      Re: PostgreSQL as a local in-memory cache  (Robert Haas, )
       Re: PostgreSQL as a local in-memory cache  (Dave Page, )
        Re: PostgreSQL as a local in-memory cache  (Tom Lane, )
         Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
         Re: PostgreSQL as a local in-memory cache  (Dimitri Fontaine, )
       Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
     Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
      Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
       Re: PostgreSQL as a local in-memory cache  (Robert Haas, )
        Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
         Re: PostgreSQL as a local in-memory cache  ("Kevin Grittner", )
         Re: PostgreSQL as a local in-memory cache  (Robert Haas, )
          Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
           Re: PostgreSQL as a local in-memory cache  (Tom Lane, )
            Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
             Re: PostgreSQL as a local in-memory cache  (Jignesh Shah, )
              Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
               Re: PostgreSQL as a local in-memory cache  (Brad Nicholson, )
                Re: PostgreSQL as a local in-memory cache  (Bruce Momjian, )
               Re: PostgreSQL as a local in-memory cache  (Jignesh Shah, )
                Re: PostgreSQL as a local in-memory cache  (Greg Smith, )
    Re: PostgreSQL as a local in-memory cache  ("Pierre C", )
     Re: PostgreSQL as a local in-memory cache  (Matthew Wakeling, )
      Re: PostgreSQL as a local in-memory cache  ("Pierre C", )
       Re: PostgreSQL as a local in-memory cache  (Josh Berkus, )
        Re: PostgreSQL as a local in-memory cache  (Rob Wultsch, )
         Re: PostgreSQL as a local in-memory cache  (Robert Haas, )
          Re: PostgreSQL as a local in-memory cache  (Josh Berkus, )
           Re: PostgreSQL as a local in-memory cache  (Pavel Stehule, )
            Re: PostgreSQL as a local in-memory cache  ("Joshua D. Drake", )
             Re: PostgreSQL as a local in-memory cache  (Pavel Stehule, )
              Re: PostgreSQL as a local in-memory cache  ("A.M.", )
               Re: PostgreSQL as a local in-memory cache  (Pavel Stehule, )
            Re: PostgreSQL as a local in-memory cache  (Josh Berkus, )
             Re: PostgreSQL as a local in-memory cache  (Pavel Stehule, )
            Re: PostgreSQL as a local in-memory cache  ("Joshua D. Drake", )
      Re: PostgreSQL as a local in-memory cache  (Josh Berkus, )
    Re: PostgreSQL as a local in-memory cache  (Josh Berkus, )
     Re: PostgreSQL as a local in-memory cache  (Tom Lane, )
   Re: PostgreSQL as a local in-memory cache  (Greg Smith, )
   Re: PostgreSQL as a local in-memory cache  (Robert Haas, )
 Re: PostgreSQL as a local in-memory cache  (Dave Crooke, )
  Re: PostgreSQL as a local in-memory cache  (Craig James, )

Robert Haas wrote:
> On Tue, Jun 29, 2010 at 9:32 AM, Bruce Momjian <> wrote:
> > Robert Haas wrote:
> >> On Mon, Jun 28, 2010 at 5:57 PM, Bruce Momjian <> wrote:
> >> >> The patch also documents that synchronous_commit = false has
> >> >> potential committed transaction loss from a database crash (as well as
> >> >> an OS crash).
> >>
> >> Is this actually true?
> >
> > I asked on IRC and was told it is true, and looking at the C code it
> > looks true. ?What synchronous_commit = false does is to delay writing
> > the wal buffers to disk and fsyncing them, not just fsync, which is
> > where the commit loss due to db process crash comes from.
>
> Ah, I see.  Thanks.

I am personally surprised it was designed that way;  I thought we would
just delay fsync.

--
  Bruce Momjian  <>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + None of us is going to be here forever. +


В списке pgsql-performance по дате сообщения:

От: "Kevin Grittner"
Дата:
Сообщение: Re: ideal storage configuration
От: Jignesh Shah
Дата:
Сообщение: Re: PostgreSQL as a local in-memory cache