Re: ThisTimeLineID in checkpointer and bgwriter processes

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