Re: ATTACH/DETACH PARTITION CONCURRENTLY

On Tue, 6 Nov 2018 at 10:10, Robert Haas <robertmhaas@gmail.com> wrote:


> With this
> approach, already-running queries won't take into account the fact
> that new partitions have been added, but that seems at least tolerable
> and perhaps desirable.
>

Desirable, imho. No data added after a query starts would be visible.


> If the
> COPY isn't trying to send any tuples to the now-detached partition,
> then it's fine, but if it is, then I have trouble seeing any behavior
> other than an error as sane, unless perhaps a new partition has been
> attached or created for that part of the key space.
>

Error in the COPY or in the DDL? COPY preferred. Somebody with insert
rights shouldn't be able to prevent a table-owner level action. People
normally drop partitions to save space, so it could be annoying if that was
interrupted.


Supporting parallel query shouldn't make other cases more difficult from a
behavioral perspective just to avoid the ERROR. The ERROR sounds annoying,
but not sure how annoying avoiding it would be.

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