Re: Gist indexes on int arrays

On Tue, 4 Mar 2003, Greg Stark wrote:

>
> Greg Stark <gsstark@MIT.EDU> writes:
>
> > Can I have a GiST index on (foo_id, attribute_set_array) and have it be just
> > as fast at narrowing the search to just foo_id = 900 but also speed up the ~
> > operation?
>
> Hm, so if I understand what I'm reading I can do this if I load the btree_gist
> contrib module as well. I'm still not sure whether it'll be worthwhile for
> this application though.
>
> I have a bit of a problem though. Is building GiST indexes supposed to take
> much much longer than building btree indexes? It's been running nearly an hour
> and it's still going. The hard drive is hardly moving so it seems to be all
> cpu usage. I don't even see any pgsql_tmp usage.
>
> db=# CREATE INDEX cache_gist_idx on cache using gist ( foo_id , attribute_set gist__int_ops);
>
> postgres 30176 86.3 22.2 64896 57344 ?       R    11:08  40:32 postgres: postgres slo [local] CREATE INDEX
>
>
> I don't remember exact numbers but building the normal btree index took on the
> order of 15m. This will have to be rebuilt nightly, an hour long index build
> won't be practical.

what's the time to create gist indices separately ? I suppose 15m is the time
to create btree index on *single* column ?

>
> --
> greg
>
>
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Regards,    Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
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