Re: ThisTimeLineID in checkpointer and bgwriter processes - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: ThisTimeLineID in checkpointer and bgwriter processes
Date
Msg-id CA+U5nMJexRwi=3ddFVUAxZ8iCQpE59MX41G2wxcFaKkBzDt5ig@mail.gmail.com
Whole thread Raw
In response to Re: ThisTimeLineID in checkpointer and bgwriter processes  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On 20 December 2012 16:21, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Simon Riggs <simon@2ndQuadrant.com> writes:
>> PreallocXlogFiles() should have been put to the sword long ago. It's a
>> performance tweak aimed at people without a performance problem in
>> this area.
>
> This claim seems remarkably lacking in any supporting evidence.
>
> I'll freely grant that PreallocXlogFiles could stand to be improved
> (by which I mean made more aggressive, ie willing to create files more
> often and/or further in advance).  I don't see how it follows that it's
> okay to remove the functionality altogether.  To the extent that we can
> make that activity happen in checkpointer rather than in foreground
> processes, it's surely a good thing.

"More aggressive" implies it is currently in some way aggressive.

Removing it will make as little difference as keeping it, so let it stay.

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services



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