Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> OK, which part of is "demonstrably false"? I think the old "should
> generally be preferred" is too vague. No one has come up with a case
> where hash has shown to be faster, and a lot of cases where it is slower.
The only thing I recall being lots worse is initial index build.
I have not tested it much, but I would expect that hash holds up better
in the presence of many equal keys than btree does...
regards, tom lane