Re: Using GIN indexes on 8.2

On Sat, 11 Nov 2006, Robert Treat wrote:

> On Friday 10 November 2006 14:41, Jeff Davis wrote:
>> On Fri, 2006-11-10 at 20:39 +0300, Teodor Sigaev wrote:
>>>>> Use @>, <@ operations instead of @ and ~
>>>>> Look for discussions in -hackers for reasons of changing names
>>>>
>>>> Ah, many thanks. How about updating those web pages? :)
>>>
>>> Now they are in core:
>>> http://developer.postgresql.org/pgdocs/postgres/functions-array.html
>>>
>>>>> Pls, why don't you use tsearch2 with GIN?
>>>>
>>>> Perhaps -- is there any documentation on this?
>>>
>>> Nothing special, just use GIN index instead of GiST.
>>
>> I think a section showing when to use GiST versus GIN would be very
>> helpful (assuming there are still good reasons to use GiST). I would
>> certainly read it.
>>
>
> I was wondering this same thing, but it appears the trade-off is disk
> space/update speed (GiST) vs. query times (Gin). Magnus had a couple of nice
> posts in his blog you might want to check out:
> http://people.planetpostgresql.org/mha/

This is written in tsearch2 documentation
http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/tsearch2-ref.html#indexes
Also, see our slides
http://www.sai.msu.su/~megera/wiki/tsearch2slides

The best practice is to use GIN for archive search and GiST for online one.
Table inheritabce with CE would help maintaining of good search performance
and fast update.

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru)
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83