Re: Bugs/slowness inserting and indexing cubes

Tom Lane wrote:
> Jay Levitt<jay.levitt@gmail.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