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Re: Materializing a sequential scan - Mailing list pgsql-performance

From Tom Lane
Subject Re: Materializing a sequential scan
Date
Msg-id 12333.1130367975@sss.pgh.pa.us
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In response to Re: Materializing a sequential scan  ("Steinar H. Gunderson" <sgunderson@bigfoot.com>)
Responses Re: Materializing a sequential scan  ("Steinar H. Gunderson" <sgunderson@bigfoot.com>)
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"Steinar H. Gunderson" <sgunderson@bigfoot.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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