Re: Why is lock not released?

Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
>> The "drop" way probably allows slightly more concurrency, but given that
>> people should seldom be taking exclusionary locks on system catalogs,
>> I'm not sure this is really an issue.

> Hmm.  The problem at hand (REASSIGN OWNED BY) may involve changing
> ownership of several objects in a single transaction.  The order is
> unspecified, because it's following a scan of the pg_shdepend entries --
> so it'd be easy for one REASSIGN OWNED BY transaction to deadlock with
> another one, if they happen to follow different orderings.

Uh, how is it going to deadlock on a lock that is not exclusive?
        regards, tom lane