Re: Terrible performance on wide selects

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От Tom Lane
Тема Re: Terrible performance on wide selects
Дата
Msg-id 25521.1043280242@sss.pgh.pa.us
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Ответ на Re: Terrible performance on wide selects  ("Dann Corbit" <DCorbit@connx.com>)
Ответы Re: Terrible performance on wide selects  (Hannu Krosing <hannu@tm.ee>)
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"Dann Corbit" <DCorbit@connx.com> writes:
> Maybe I don't really understand the problem, but it seems simple enough
> to do it once for the whole query.

We already do cache column offsets when they are fixed.  The code that's
the problem executes when there's a variable-width column in the table
--- which means that all columns to its right are not at fixed offsets,
and have to be scanned for separately in each tuple, AFAICS.

            regards, tom lane

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