
Checking application/pgp-signature: FAILURE
-- Start of PGP signed section.
> Hi -
> 
> pgman wrote:
> 
> : Most Unix filesystems will not allocate disk blocks until you write in
> : them.  [...]
> 
> Yes, I understand that, but how is it a problem for postgresql?

Uh, I thought we did that so we were not allocating file system blocks
during WAL writes.  Performance is bad when we do that.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Tue, 17 Jul 2001 15:18:40 -0400 (EDT)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: Re: Idea: recycle WAL segments, don't delete/recreate
 'em
Bruce Momjian wrote:
>
> Checking application/pgp-signature: FAILURE
> -- Start of PGP signed section.
> > Hi -
> >
> > pgman wrote:
> >
> > : Most Unix filesystems will not allocate disk blocks until you write in
> > : them.  [...]
> >
> > Yes, I understand that, but how is it a problem for postgresql?
>
> Uh, I thought we did that so we were not allocating file system blocks
> during WAL writes.  Performance is bad when we do that.

    Performance isn't the question. The problem is when you get a
    "disk full" just in the middle of the need to write important
    WAL  information. While preallocation of a new WAL file, it's
    OK and controlled, but there are more  delicate  portions  of
    the code.


Jan

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Tue, 17 Jul 2001 16:36:56 -0400 (EDT)
Jan Wieck <JanWieck@Yahoo.com>
Re: Re: Idea: recycle WAL segments, don't delete/recreate
 'emm