Re: USING HASH considered harmful?

> > > I guess this is because PG really has to lock the hash table entry in
> > > both cases. It does, however, make HASH indices completely useless for
> > > any table that you might want to update.
> > >
> > > Is this a known feature?
> >
> > Yes, I have heard about this problem.  Would you test btree vs hash and
> > report back which is faster.  I have requested this from >20 people and
> > no one reported back.
>
> I changed to hash because it was marginally faster for the queries
> we were doing - maybe 5% or so. It was very marginal, but we
> need every bit of performance we can get.

Thanks.  Very valuable information.  It tells us that it may be worth
trying to optimize it someday.

--
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