Re: Let's invent a function to report lock-wait-blocking PIDs

On Thu, Mar 21, 2013 at 12:03:21AM +0100, Dimitri Fontaine wrote:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
> >>   pg_is_lock_exclusive(lock, lock) returns boolean
> >>   pg_is_lock_exclusive(lock[], lock[]) returns boolean
> >
> >> I suppose that the lock type would be text ('ExclusiveLock'), but we
> >> could also expose a new ENUM type for that (pg_lock_mode).
> >
> > I don't have an objection to providing such a function, but it doesn't
> > do anything for the problem beyond allowing getting rid of the hairy
> > case expression.  That's a good thing to do of course --- but what about
> > the indirect-blockage issue?
> 
> It's too late for my brain to build the full answer, the idea is that we
> have another way to build the dependency cycles in the pg_locks query
> and then we can aggregate locks at each level and see about conflicts
> once we accumulated the data.
> 
> Is that even possible? E_GOTOSLEEP.

Should this be a TODO?

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +