Re: Excessive (and slow) fsync() within single transaction

From: Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
To: Stephen Tyler <stephen(at)stephen-tyler(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Excessive (and slow) fsync() within single transaction
Date: 2009-12-09 21:02:46
Message-ID: dcc563d10912091302r44a7ee52jb2b9ff2ee93f0c99@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

On Wed, Dec 9, 2009 at 5:11 AM, Stephen Tyler <stephen(at)stephen-tyler(dot)com> wrote:
> The times are apparently in milliseconds.  But that doesn't make any sense
> for the 7200rpm SATA HDD, given it has an 8.3ms rotation time.  And the
> numbers for the SSD are basically identical to the HDD, apart from the bare
> write timing.
>
> Do I conclude that the sync timings are all faked by the OS?

Actually, it's usually the drives that lie about fsync, especially
consumer grade (and some server grade) SATA / PATA drives are known
for this.

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Ron Mayer 2009-12-09 21:35:24 Re: Excessive (and slow) fsync() within single transaction
Previous Message CG 2009-12-09 19:31:08 pg_dump and ON DELETE CASCADE problem