Re: Update on tables when the row doesn't change

Hi All,

Can someone please address this aspect of Sebastian's email?  I, too, am
interested in the response.

>> Why does Postgres perform an update on the table even
>> if no data changes?
>> Can I circumvent this behaviour of Postgres?

Tim

-----Original Message-----
From: pgsql-general-owner@postgresql.org
[mailto:pgsql-general-owner@postgresql.org] On Behalf Of Sebastian Böck
Sent: Tuesday, May 24, 2005 8:06 AM
To: pgsql-general@postgresql.org
Subject: [GENERAL] Update on tables when the row doesn't change

Hi all,

Maybe it's a very silly question, but why does Postgres perform an update on
the table even if no data changes?

I recognized this recently doing a rewrite of my rules because they took to
long. I had many conditional rules I collapsed to one unconditional rule, so
that the views get constructed only once. If I split these updates to the
underlying tables, I get a lot of updates which don't perform any "real"
updates.

Can I circumvent this behaviour of Postgres only by defining lot of rules /
triggers on these underlying table are there some trickier ways?

Any help appreciated,

Sebastian

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