Re: What is wrong with hashed index usage?

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I remember three problems:  build time, index size, and concurrency
> problems.  I was wondering about the equal key case myself, and assumed
> hash may be a win there, but with the concurrency problems, is that even
> possible?

Sure.  Many-equal-keys are a problem for btree whether you have any
concurrency or not.

> OK, I have reworded it.  Is that better?

It's better, but you've still discarded the original's explicit mention
of concurrency problems.  Why do you want to remove information?

> How about an elog(NOTICE) for hash use?

I don't think that's appropriate.
        regards, tom lane