On Fri, 8 May 2020 at 13:51, github kran <githubkran@gmail.com> wrote: > I can't either DROP or ALTER any other tables ( REMOVE Inheritance for any of old tables where the WRITES are not getting written to). Any of the ALTER TABLE OR DROP TABLE DDL's arer not getting exeucted even I WAITED FOR SEVERAL MINUTES , so I have terminated those queries as I didn't have luck.
The auto-vacuum freeze holds an SharedUpdateExclusiveLock on the table being vacuumed. If you try any DDL that requires an AccessExclusiveLock, it'll have to wait until the vacuum has completed. If you leave the DDL running then all accesses to the table will be queued behind the ungranted AccessExclusiveLock. It's likely a good idea to always run DDL with a fairly short lock_timeout, just in case this happens.
How much value I can assign to lock_timeout so that I dont get into trouble to test my DDL commands and without impacting other sessions.
> 3) Can I increase the autovacuum_freeze_max_age on the tables on production system ?
Yes, but you cannot increase the per-table setting above the global setting. Changing the global setting requires a restart.
How can I change the value of the global setting of the autovacuum_freeze_max_Age value.