David Fetter napsal(a):
> On Tue, Aug 19, 2008 at 09:50:53PM -0400, Tom Lane wrote:
>> David Fetter <david@fetter.org> writes:
>>> On Tue, Aug 19, 2008 at 07:45:16PM -0400, Tom Lane wrote:
>>>> FWIW, given that there will probably always be corner cases. I can
>>>> see the attraction in Simon's suggestion of providing a way to
>>>> manually issue a system-wide forced plan flush.
>>> Would that require a system-wide plan cache to implement?
>> No, just a function that can issue a suitable sinval message.
>>
>> plancache.c would already respond in the desired way to a relcache inval
>> message with OID = 0, though likely it'll be cleaner to invent an sinval
>> message type specifically for the purpose.
>>
>> One thing to think about is whether the flush should be truly
>> system-wide or just database-wide. I can see a lot more uses for the
>> latter than the former --- I don't think there's a reason for cached
>> plans to depend on any contents of the shared catalogs.
>
> They might during an on-line upgrade.
>
At this moment we have offline catalog upgrade. On-line old catalog
processing is nice idea but amount of work and impact is too high to do
it. Catalog is usually small and its offline upgrade is fast.
Zdenek