On Wed, Feb 4, 2009 at 4:23 PM, Jeff Davis <pgsql@j-davis.com> wrote:
> On Wed, 2009-02-04 at 14:40 -0500, Robert Haas wrote:
>> Well, there's nothing to force that plan to be invalidated when the
>> state of the pending list changes, is there?
>>
>
> Would it be unreasonable to invalidate cached plans during the pending
> list cleanup?
>
> Anyway, it just strikes me as strange to expect a plan to be a good plan
> for very long. Can you think of an example where we applied this rule
> before?
Well, I am not an expert on this topic.
But, plans for prepared statements and statements within PL/pgsql
functions are cached for the lifetime of the session, which in some
situations could be quite long.
I would think that invalidating significantly more often would be bad
for performance.
...Robert