Re: Bugs/slowness inserting and indexing cubes

Tom Lane wrote:
> Jay Levitt<jay(dot)levitt(at)gmail(dot)com> writes:
>> [Posted at Andres's request]
>> TL;DR: Inserting and indexing cubes is slow and/or broken in various ways in
>> various builds.
>
>> 1. In 9.1.2, inserting 10x rows takes 19x the time.
>> - 9.1-HEAD and 9.2 "fix" this; it now slows down linearly
>> - but: 10s> 8s> 5s!
>> - but: comparing Ubuntu binary w/vanilla source build on virtual disks,
>> might not be significant
>
> FWIW, I find it really hard to believe that there is any real difference
> between 9.1.2 and 9.1 branch tip on this. There have been no
> significant changes in either the gist or contrib/cube code in that
> branch. I suspect you have a measurement issue there.

I suspect you're right, given that five runs in a row produced times from 7s
to 10s. I just wanted to include it for completeness and in case it
triggered any "a-ha" moments.

>> 4. 9.1-HEAD never successfully indexes 10 million rows ("never" = at least
>> 20 minutes on two runs; I will follow up in a few hours)
>
> Works for me (see above), though it's slower than you might've expected.

So my pre-built 9.1.2 takes 434s, my source-built 9.2 takes 509s, and
(probably both of our) 9.1-HEAD takes 1918s... is that something to worry
about, and if so, are there any tests I can run to assist? That bug doesn't
affect me personally, but y'know, community and all that. Also, I wonder if
it's something like "9.2 got way faster doing X, but meanwhile, HEAD got way
slower doing Y.", and this is a canary in the coal mine.

Jay