On Sat, Feb 25, 2017 at 11:24 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > Patch to reduce lock levels of various relation-level options, > following on from earlier work by Fabrizio, with additional work and > documentation by me.
I have reviewed this patch and I think it looks reasonable. I think that the behavior will be that overlapping transactions may or may not pick up the new values depending on whether they already have a lock on the relation and whether they happen to have a relcache flush for some other reason, but new transactions started after the value is altered via DDL should always see the new value, because they will always do AcceptInvalidationMessages() after locking the relation, and if they haven't yet picked up the value by that point, then they will see it then. If that sounds right, maybe we should document someplace in the SGML documentation that new values of reloptions which can be changed without AEL might or might not be seen by overlapping transactions; perhaps the lock levels for each reloption should also be documented (since, as evidenced by this and previous patches, people obviously do care about what those levels are). -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
