On Wed, Oct 15, 2014 at 10:04 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Amit Kapila <amit.kapil...@gmail.com> writes: >> I have observed that for renaming some of the objects >> AccessExclusiveLock is taken on object whereas for >> other kind of objects no lock is taken on object before >> renaming the object. > > The usual theory for DDL updates of all types (not just rename) > is that an explicit lock is only needed for objects whose catalog > representation comprises more than one row. Otherwise, the implicit > locking involved in updating that row is sufficient to serialize > different updates.
That's an interesting point that I hadn't considered, but I'm willing to believe that at least some of the differences might also be haphazard. -- 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
