Re: [GENERAL] Re: [SQL] bad select performance fixed by forbidding hash joins

> George Young <gry(at)ll(dot)mit(dot)edu> writes:
> > Yes! PGOPTIONS="-fh" made the query time go from 16 seconds to 2 seconds!
> > Is this a safe thing to leave on permanently, or is there some way to set
> > PGOPTIONS for just this query?
>
> I wouldn't recommend leaving it on as a long-term solution, because
> you're hobbling the system for cases where hashjoin *is* the best
> method. AFAIK there is not a SET VARIABLE method for enabling/disabling
> plan types on-the-fly, though perhaps one should be added.

Postgres does have options to prohibit certain join types, so you could
try forcing a certain join type and see what happens.

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