Re: [GENERAL] Creation of tsearch2 index is very slow

From: Martijn van Oosterhout <kleptog(at)svana(dot)org>
To: Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Ron <rjpeace(at)earthlink(dot)net>, pgsql-performance(at)postgresql(dot)org
Subject: Re: [GENERAL] Creation of tsearch2 index is very slow
Date: 2006-01-21 20:35:58
Message-ID: 20060121203558.GC9955@svana.org
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On Sat, Jan 21, 2006 at 06:22:52PM +0300, Oleg Bartunov wrote:
> >I see how it works, what I don't quite get is whether the "inverted
> >index" you refer to is what we're working with here, or just what's in
> >tsearchd?
>
> just tsearchd. We plan to implement inverted index into PostgreSQL core
> and then adapt tsearch2 to use it as option for read-only archives.

Hmm, had a look and think about it and I think I see what you mean by
an inverted index. I also think your going to have a real exercise
implementing it in Postgres because postgres indexes work on the basis
of one tuple, one index entry, which I think your inverted index
doesn't do.

That said, I think GiST could be extended to support your case without
too much difficulty. Interesting project though :)

BTW, given you appear to have a tsearch2 index with some real-world
data, would you be willing to try some alternate picksplit algorithms
to see if your gevel module shows any difference?

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

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