Re: [PATCHES] Last infomask bit

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От Heikki Linnakangas
Тема Re: [PATCHES] Last infomask bit
Дата
Msg-id 45A4B285.7090004@enterprisedb.com
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Ответ на Re: [PATCHES] Last infomask bit  (Tom Lane <tgl@sss.pgh.pa.us>)
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Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
>> Tom Lane wrote:
>>> Has anyone bothered to measure the overhead added by having to mask to
>>> fetch or store the natts value?  This is not a zero-cost improvement.

I haven't tested it. Agreed, it does add an AND operation to places
where t_natts is accessed.

>> Tom, how should this be tested?  I assume some loop of the same query
>> over and over again.
>
> I'd be satisfied by a demonstration of no meaningful difference in
> pgbench numbers.
>
> It's *probably* not a problem, but you never know if you don't check...

I doubt there's any measurable difference, but I can do a pgbench run to
make sure.

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com

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