On Tue, Aug 11, 2015 at 2:57 PM, Michael Paquier <michael.paqu...@gmail.com> wrote: > On Tue, Aug 11, 2015 at 2:42 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> Tatsuo Ishii <is...@postgresql.org> writes: >>> I think this is because pg_control on the standby remembers that the >>> previous primary server's max_connections = 1100 even if the standby >>> server fails to start. Shouldn't we update pg_control file only when >>> standby succeeds to start? >> >> Somebody refresh my memory as to why we have this restriction (that is, >> slave's max_connections >= master's max_connections) in the first place? >> Seems like it should not be a necessary requirement, and working towards >> getting rid of it would be far better than any other answer. > > If I recall correctly, that's because KnownAssignedXIDs and the lock > table need to be large enough on the standby for the largest snapshot > possible (procarray.c).
... And the maximum number of locks possible on master (for the lock table, wasn't it for the concurrent number of AccessExclusiveLocks, btw?). -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
