Re: 64-bit CommandIds - Mailing list pgsql-patches

From Tom Lane
Subject Re: 64-bit CommandIds
Date
Msg-id 19319.1209133715@sss.pgh.pa.us
Whole thread Raw
In response to Re: 64-bit CommandIds  (Hans-Juergen Schoenig <hs@cybertec.at>)
Responses Re: 64-bit CommandIds  (Hans-Juergen Schoenig <hs@cybertec.at>)
List pgsql-patches
Hans-Juergen Schoenig <hs@cybertec.at> writes:
> Alvaro Herrera wrote:
>> Question for Hans-Juergen and Zoltan: have you tested 8.3 and do you
>> still see the need for this?

> i have seen this problem two or three times within the past 2-3 years or
> so. so, it can basically happen in the field for some special purpose
> applications but i don't see this as an every day problem. it would be
> nice to have it in.

So these experiences were pre-8.3, right?

The reason that I'm harping on that is that plpgsql does a
CommandCounterIncrement for each expression it evaluates, whether
or not there's any visible database access.  As of 8.3 that won't
cause consumption of CIDs, but before it did.  I suspect that in a
lot of real-world scenarios, CID consumption from triggers will be
down by an order of magnitude.

            regards, tom lane

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