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Re: Rewritten rows on unchanged values

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Hi folks,


On 2013-03-22 13:32, Bertrand Janin wrote:
>    UPDATE demo
>    SET value = value
>    WHERE id = 1;


On 2013-03-22 14:55, Tom Lane wrote:
>
It's not *necessary* to do so.  However, avoiding it would require
sitting there and comparing the old and new tuples,


But in this case, no tuples would need to be compared: just by looking at the query is becomes clear that it is a no-op.
Isn't this something the planner is or could be aware of?

Betrand, out of curiosity: is this a synthentic test case or do you really have an application that generates queries like this?


Best regards,

	-hannes


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