> I saw Tom answer a similar question a year ago, by saying that the
> hash access method is poorly supported and that there is no advantage
> to using it. I am not sure about the former, but the latter is not
> entirely true: we saw at least 20% gain in performance when we
> switched from btree to hash, and my boss considers 20% a big enough
> improvement. Besides, he knows the database theory and he is a
> long-time BerkelyDB user, and in his world, hash is greatly superior
> to btree, so he is wondering why are the postgres implementations so
> close. Besides, it's a tough challenge to explain it to a Libertarian
> that he'd better not do something.
>
> I guess we can make such people happy by either fixing hash, or by
> making btree very much worse -- whichever is easier :)
Cool. I'm sure that making btree much worse is definitely within my
ability - I'll submit a patch shortly with new pg_bench results.
Chris