Re: Seq scans status update

Heikki Linnakangas <heikki@enterprisedb.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