On Fri, Aug 04, 2006 at 10:52:34AM +0200, Guillaume Smet wrote:
> On 8/4/06, Luke Lonergan <llonergan@greenplum.com> wrote:
> >My ordering of this list in terms of priority is:
> >
> >1) Windowing functions
> >2) MERGE
> >3) Index only access (new)
> >4) In-place upgrades
>
> And what about compression of on-disk sorting? There has been a long
> thread about this idea. Is there any news about this feature? IIRC Jim
> Nasby and Martijn were working on testing that and on validating it
> was interesting for most of the cases.
Well, I posted a bunch of numbers, but people wanted more proof. Which I
haven't had time to generate yet.
If someone wants to pick up the ball and run with it, do some testing of
SELECT random() AS r INTO test_table FROM generate_series(1,some_big_number);
\t
SELECT count(*) FROM (SELECT r FROM test_table ORDER BY r);
This is about the worst-case test I can think of; if it still shows
improvement here...
BTW, I suspect it was too late for this to get into 8.2 over a month
ago, as the patch that's floating around has some rather serious issue
in it that would limit usability too much... something about specific
sort modes or some such that I don't recall anymore. My intention was
to try and finish testing after 8.2 when it was more likely that someone
could look into whatever that issue was.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461