Re: GIST create index very very slow

On 08/18/2014 07:47 PM, Robert Haas wrote:
> I think something's missing from your report, though, because if there
> is 3.5 Mb/s of write I/O and only 8 b/s of file growth, nearly all of
> the writes are doing something other than extending that file.

Hmm. Sounds like it's churning through temporary files. Gist build
creates a bunch of buffers that spill to disk, to temporary files, until
it begins writing the tuples out to the actual relation.

But there haven't been any changes to that since 9.1, when the new gist
build algorithm was introduced. Make sure you have maintenance_work_mem
set high enough; that affects the size of the gist build buffers.

Worthy7, you'll have to provide a lot more details for anyone to help
you further. A reproducible test case would be ideal.

- Heikki