On 2020-Nov-30, Justin Pryzby wrote: > On Tue, Nov 03, 2020 at 08:56:06PM -0300, Alvaro Herrera wrote:
> > * On the first transaction (the one that marks the partition as > > detached), the partition is locked with ShareLock rather than > > ShareUpdateExclusiveLock. This means that DML is not allowed anymore. > > This seems a reasonable restriction to me; surely by the time you're > > detaching the partition you're not inserting data into it anymore. > > I don't think it's an issue with your patch, but FYI that sounds like > something > I had to do recently: detach *all* partitions of various tabls to promote > their > partition key column from timestamp to timestamptz. And we insert directly > into child tables, not routed via parent. > > I don't your patch is still useful, but not to us. So the documentation > should > be clear about that. FWIW since you mentioned this detail specifically: I backed away from doing this (and use ShareUpdateExclusive), because it wasn't buying us anything anyway. The reason for it is that I wanted to close the hole for RI queries, and this seemed the simplest fix; but it really *wasn't* a fix anyway. My later games with the active snapshot (which are present in the version I pushed) better close this problem. So I don't think this would be a problem. -- Álvaro Herrera Valdivia, Chile
