Re: 7.4 - FK constraint performance

On Thu, 2004-02-12 at 23:25, Tom Lane wrote:
> Rod Taylor <rbt@rbt.ca> writes:
> > Statistics say there are 10 values. Statistics list the 10 most common
> > values (all of them). Given this, would it not be reasonable to assume
> > that 239 is a recent addition (if there at all) to the table and not
> > very common?
>
> We don't know that it's 239 when we make the plan.  In order to know
> that, we'd have to abandon caching of RI check query plans and re-plan
> for each row.  That strikes me as inevitably a losing proposition.

Right, sorry, I forgot this was out of a fk trigger.

--
Rod Taylor <rbt [at] rbt [dot] ca>

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