Обсуждение: A few notes

Hello. I thought I'd just toss out a few thoughts:

1) Should a link to the release changes for 7.3.3 be on the website? I
had to look into the web-interface of CVS to see what was actually
changed.

2) It would be nice if some regular performance tests could be done
upon every release on some stock machine whose configuration never
changes to give some numerical hints as to the value of an upgrade.

3) I got bit by using the explicit join syntax just like Thomas
Lockhart had predicted. I then removed the syntax to let the planner
do its job. Queries which took around 10 seconds took 5 minutes. I
then disabled GEQO and the queries ran in around a second. I noticed
that the explicit join syntax will no longer confine planning choices
in 7.4, but is it possible the GEQO threshold, as a default, is too low?

Mike Mascari
mascarm@mascari.com

Mike Mascari <mascarm@mascari.com> writes:
> ... is it possible the GEQO threshold, as a default, is too low?

It's been on the TODO list for awhile to investigate whether the current
default is still appropriate.  A lot of planner details have changed
since we last twiddled it, and you're not the first to suggest that it
may need to be twiddled again.  But no one's provided more than
anecdotal evidence.  If you want to do some measurements to determine
where the best crossover point is now, go to it ...
        regards, tom lane