Re: ATTACH/DETACH PARTITION CONCURRENTLY

On 2018-Dec-20, Robert Haas wrote:

> I didn't handle that. If partition pruning relies on nothing changing
> between planning and execution, isn't that broken regardless of any of
> this? It's true that with the simple query protocol we'll hold locks
> continuously from planning into execution, and therefore with the
> current locking regime we couldn't really have a problem. But unless
> I'm confused, with the extended query protocol it's quite possible to
> generate a plan, release locks, and then reacquire locks at execution
> time. Unless we have some guarantee that a new plan will always be
> generated if any DDL has happened in the middle, I think we've got
> trouble, and I don't think that is guaranteed in all cases.

Oh, so maybe this case is already handled by plan invalidation -- I
mean, if we run DDL, the stored plan is thrown away and a new one
recomputed. IOW this was already a solved problem and I didn't need to
spend effort on it. /me slaps own forehead

--
Álvaro Herrera https://www.2ndQuadrant.com/
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