Re: Materializing a sequential scan

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Steinar H(dot) Gunderson" <sgunderson(at)bigfoot(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Materializing a sequential scan
Date: 2005-10-26 23:06:15
Message-ID: 12333.1130367975@sss.pgh.pa.us
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"Steinar H. Gunderson" <sgunderson(at)bigfoot(dot)com> writes:
> Any good ideas why 8.1 would refuse to do this, when 7.4 would do it? It does
> not matter how high I set my work_mem; even at 2.000.000 it refused to hash
> the subplan.

AFAICS, subplan_is_hashable() is testing the same conditions in 7.4 and
HEAD, so this isn't clear. Want to step through it and see where it's
deciding not to hash?

regards, tom lane

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