Re: Fixing GIN for empty/null/full-scan cases

On Jan 14, 2011, at 11:37 PM, David E. Wheeler wrote:

>> Hard to comment on any of this without a concrete example (including
>> data) to look at. Given the bugs we've recently found in the picksplit
>> algorithms for other contrib modules, I wouldn't be too surprised if the
>> sucky GiST performance traced to a similar bug in intarray. But I'm not
>> excited about devising my own test case.

FWIW, it looks like we're able to fix the GiST performance by using gist__intbig_ops. Relevant thread:

http://archives.postgresql.org/pgsql-performance/2009-03/msg00254.php

Perhaps time to revisit using gist__int_ops as the default?

> I could give you access to the box in question if you'd like to poke at it. Send me a public key.
>
>> One other point here is that GIN index build time is quite sensitive to
>> maintenance_work_mem --- what did you have that set to?
>
> 64MB

Best,

David