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.

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026