Re: Modifying TOAST thresholds

tgl(at)sss(dot)pgh(dot)pa(dot)us (Tom Lane) writes:
> Chris Browne <cbbrowne(at)acm(dot)org> writes:
>> bruce(at)momjian(dot)us (Bruce Momjian) writes:
>>> I have seen no one do peroformance testing of this, so it seems it
>>> will have to wait for 8.4.
>
>> I didn't have time...
>
>> (e.g. - we've got a case where dropping the threshold to ~900 bytes
>> would give us a big win for certain databases and tables.)
>
> How do you know? Seems like you've got a readymade test case there.

I did some testing with Known Scenario, and found, indeed, that there
was a significant gain to be had. I documented it at least partially
on March 21...

<http://www.nabble.com/Re%3A-TOASTing-smaller-things-p9602766.html>

Unfortunately, the sample query that I used to validate usefulness
isn't one I can share :-(.

More importantly, it's only one test case, and is strongly influenced
by some *very* strong regularity to the patterns of updates that take
place to the table that I looked at. It's not nearly good enough to
treat as a generalizable case.
--
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