Re: Terrible performance on wide selects - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Terrible performance on wide selects
Date
Msg-id 25738.1043333402@sss.pgh.pa.us
Whole thread Raw
In response to Re: Terrible performance on wide selects  (Daniel Kalchev <daniel@digsys.bg>)
List pgsql-hackers
Daniel Kalchev <daniel@digsys.bg> writes:
> Does this mean, that constructing tables where fixed length fields are
> 'before' variable lenght fields and 'possibly null' fields might increase
> performance?

There'd have to be no nulls, period, to get any useful performance
difference --- but yes, in theory putting fixed-length columns before
variable-length ones is a win.

I wouldn't bother going out to rearrange your schemas though ... at
least not before you do some tests to prove that it's worthwhile.

            regards, tom lane

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