On 1 November 2017 at 01:55, Peter Geoghegan <p...@bowt.ie> wrote: > The problem here is: Iff the first statement uses ON CONFLICT > infrastructure, doesn't the absence of WHEN NOT MATCHED imply > different semantics for the remaining updates and deletes in the > second version of the query? You've removed what seems like a neat > adjunct to the MERGE, but it actually changes everything else too when > using READ COMMITTED.
Would these concerns be alleviated by adding some kind of Pg-specific decoration that constrained concurrency-safe MERGEs? So your first statement would be MERGE CONCURRENTLY ... and when you removed the WHEN NOT MATCHED clause it'd ERROR because that's no longer able to be done with the same concurrency-safe semantics? I don't know if this would be helpful TBH, or if it would negate Simon's compatibility goals. Just another idea. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
