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

From Tom Lane
Subject Re: Terrible performance on wide selects
Date
Msg-id 25725.1043281804@sss.pgh.pa.us
Whole thread Raw
In response to Re: Terrible performance on wide selects  ("Dann Corbit" <DCorbit@connx.com>)
List pgsql-hackers
"Dann Corbit" <DCorbit@connx.com> writes:
> For the disk case, why not have the start of the record contain an array
> of offsets to the start of the data for each column?  It would only be
> necessary to have a list for variable fields.

No, you'd need an entry for *every* column (or at least, every one to
the right of the first variable-width column or NULL).  That's a lot of
overhead, especially in comparison to datatypes like bool or int4 ...

            regards, tom lane

pgsql-hackers by date:

Previous
From: "Dann Corbit"
Date:
Subject: Re: Terrible performance on wide selects
Next
From: "Dann Corbit"
Date:
Subject: Re: Terrible performance on wide selects