On 2015-08-03 14:15:27 +0900, Michael Paquier wrote: > On Sat, Aug 1, 2015 at 9:20 PM, Andres Freund wrote: > > On August 1, 2015 2:17:24 PM GMT+02:00, Michael Paquier wrote: > >>> For instance, if you told me to choose between ShareLock and > >>> ShareUpdateExclusiveLock I wouldn't know which one is strongest. I > >>> don't it's sensible to have the "lock mode compare" primitive > >>honestly. > >>> I don't have any great ideas to offer ATM sadly. > >> > >>Yes, the thing is that lowering the lock levels is good for > >>concurrency, but the non-monotony of the lock levels makes it > >>impossible to choose an intermediate state correctly. > > > > How about simply acquiring all the locks individually of they're different > > types? These few acquisitions won't matter. > > As long as this only applies on master, this may be fine... We could > basically pass a LOCKMASK to the multiple layers of tablecmds.c > instead of LOCKMODE to track all the locks that need to be taken, and > all the relations open during operations.
This sounds far too complicated to me. Just LockRelationOid() the relation with the appropriate level everytime you pass through the function? -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
