Re: Seq scans status update

Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
> I've completed a set of performance tests on a test server. The server
> has 4 GB of RAM, of which 1 GB is used for shared_buffers.

Perhaps I'm misreading it, but these tests seem to show no improvement
worth spending any effort on --- some of the tests improve a bit but
many get worse, and that's for tests allegedly designed to highlight the
improvement; there's been no attempt to measure the distributed cost of
the additional logic in scenarios where it's not helpful. To say
nothing of the likelihood that it will be flat-out counterproductive
in yet other scenarios.

regression=# select id,sum(rt),count(*) from times group by id;
id | sum | count
------------+-----------------+-------
10G | 01:15:53.497114 | 20
10Gpatched | 01:12:51.749906 | 20
2G | 00:11:54.343741 | 20
2Gpatched | 00:11:32.482733 | 20
(4 rows)

Should we not just reject the patch and move on to something more
useful?

regards, tom lane