On 02/05/17 16:14, Petr Jelinek wrote: > On 02/05/17 15:31, Tom Lane wrote: >> Petr Jelinek <petr.jeli...@2ndquadrant.com> writes: >>> Let me expand, if we don't drop the slot by default when dropping >>> subscription, we'll have a lot of users with dead slots laying around >>> holding back WAL/catalog_xmin, that's really bad. If we do drop by >>> default like now, we need option to not do that, neither RESTRICT, nor >>> CASCADE fit that. >> >> I'm not sure which part of "you can't have an option in DROP" isn't >> clear to you. Whatever the default behavior is always has to work, >> because that is what's going to happen during DROP OWNED BY, or >> DROP DATABASE. > > You are saying it like there was some guarantee that those commands > can't fail because of other objects. AFAIK for example drop database can > trivially fail just because there is replication slot in it before PG10 > (IIRC Craig managed to fix that in 10 for unrelated reasons). >
Btw looks like I already forgot how this stuff behaves. Existence of subscription currently also prevents DROP DATABASE (for same reason active backends do). DROP OWNED BY ignores SUBSCRIPTION too now, although I think it might not be strictly necessary to stay that way. But if we keep this behavior then the point about these two commands cascading to subscriptions is largely moot. -- Petr Jelinek 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
