Re: [HACKERS] Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Tom Lane <tgl@sss.pgh.pa.us>

Cc: Andres Freund <andres@anarazel.de>, Greg Stark <gsstark@mit.edu>, pgsql-hackers@postgresql.org, pgsql-performance@postgresql.org, Michael Clemmons <glassresistor@gmail.com>, Hannu Krosing <hannu@2ndquadrant.com>, Scott Marlowe <scott.marlowe@gmail.com>

Date: 2010-02-02T18:14:40Z

Lists: pgsql-hackers, pgsql-performance

On Tue, Feb 2, 2010 at 12:50 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Andres Freund <andres@anarazel.de> writes:
>> On Tuesday 02 February 2010 18:36:12 Robert Haas wrote:
>>> I took a look at this patch today and I agree with Tom that
>>> pg_fsync_start() is a very confusing name.  I don't know what the
>>> right name is, but this doesn't fsync so I don't think it shuld have
>>> fsync in the name.  Maybe something like pg_advise_abandon() or
>>> pg_abandon_cache().  The current name is really wishful thinking:
>>> you're hoping that it will make the kernel start the fsync, but it
>>> might not.  I think pg_start_data_flush() is similarly optimistic.
>
>> What about: pg_fsync_prepare().
>
> prepare_for_fsync()?

It still seems mis-descriptive to me.  Couldn't the same routine be
used simply to abandon undirtied data that we no longer care about
caching?

...Robert