On Fri, May 26, 2006 at 09:21:44PM +0100, Simon Riggs wrote:
> On Fri, 2006-05-26 at 14:47 -0500, Jim C. Nasby wrote:
> 
> > But the meat is:
> >                                         -- work_mem --
> >                         Scale           2000    20000
> > not compressed          150             805.7   797.7
> > not compressed          3000            17820   17436
> > compressed              150             371.4   400.1
> > compressed              3000            8152    8537
> > compressed, no headers  3000            7325    7876
> 
> Since Tom has committed the header-removing patch, we need to test
> 
>       not compressed, no headers v compressed, no headers

                                        -- work_mem --
                        Scale           2000    20000
not compressed          150             805.7   797.7
not compressed          3000            17820   17436
not compressed, no hdr  3000            14470   14507
compressed              150             371.4   400.1
compressed              3000            8152    8537
compressed, no headers  3000            7325    7876

> There is a noticeable rise in sort time with increasing work_mem, but
> that needs to be offset from the benefit that in-general comes from
> using a large Heap for the sort. With the data you're using that always
> looks like a loss, but that isn't true with all input data orderings.

I thought that a change had been made to the on-disk sort specifically to
eliminate the problem of more work_mem making the sort take longer. I also
thought that there was something about that fix that was tunable.
-- 
Jim C. Nasby, Sr. Engineering Consultant      [EMAIL PROTECTED]
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461

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