Re: Calculation of unused columns - Mailing list pgsql-performance

From Tom Lane
Subject Re: Calculation of unused columns
Date
Msg-id 8181.1255974200@sss.pgh.pa.us
Whole thread Raw
In response to Re: Calculation of unused columns  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Calculation of unused columns  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-performance
Simon Riggs <simon@2ndQuadrant.com> writes:
> On Sat, 2009-10-17 at 21:41 -0400, Tom Lane wrote:
>> one thing we'd have to consider
>> is whether it is okay to suppress calculation of columns containing
>> volatile functions.

> I think we should have a 4th class of functions,
> volatile-without-side-effects (better name needed, obviously).

What for?  There wouldn't be that many, I think.  random() and
clock_timestamp(), yeah, but most volatile user-defined functions
are either volatile-with-side-effects or misdeclared.

            regards, tom lane

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