Re: Review observations for partial REFRESH MATERIALIZED VIEW patc

On 5/19/26 7:42 AM, vellaipandiyan sm wrote:
> I reviewed the REFRESH MATERIALIZED VIEW ... WHERE patch and had a few
> questions around concurrency semantics.
>
> * The original DELETE -> INSERT approach exposing a consistency gap
> makes sense, especially once tuple locks disappear after DELETE. The
> newer FOR UPDATE + single-CTE approach seems safer, though I wonder
> whether overlapping refreshes could still encounter deadlock
> scenarios around UPSERT conflicts.
> * The CONCURRENTLY behavior also feels somewhat unintuitive here. With
> WHERE refreshes, the non-CONCURRENT path appears more permissive for
> writers than CONCURRENTLY WHERE, which seems opposite to the
> expectation established by normal REFRESH MATERIALIZED VIEW semantics.
> * It may also help to document the intended guarantees around
> overlapping partial refreshes and concurrent DML on base tables.

Hi,

Thanks for the review, but please reply-all to the original thread when
you review a patch so the original author and previous reviewers can see
your review.

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--
Andreas Karlsson
Percona