Re: AW: timeout on lock feature

Added to TODO:

* Add SET parameter to timeout if waiting for lock too long

>
> > I was thinking SET because UPDATE does an auto-lock.
>
> Optimal would imho be a SET that gives a maximum amount of time in seconds
> the client is willing to wait for any lock. But I liked the efficiency of Henryk's code.
>
> >
> > > Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > > > I can imagine some people wanting this. However, 7.1 has new deadlock
> > > > detection code, so I would you make a 7.1 version and send it over. We
> > > > can get it into 7.2.
> > >
> > > I object strongly to any such "feature" in the low-level form that
> > > Henryk proposes, because it would affect *ALL* locking. Do you really
> > > want all your other transactions to go belly-up if, say, someone vacuums
> > > pg_class?
>
> Yes, if a non batch client already blocked for over x seconds. Of course a more
> sophisticated client can send querycancel() but that involves a more complicated
> program (threads, timer ...).
>
> > >
> > > A variant of LOCK TABLE that explicitly requests a timeout might make
> > > sense, though.
>
> I do not think that a solution for one particular lock is very helpful. If your dml then
> blocks on some unforseen lock (parse, plan ...) , the client is in exactly the situation
> it tried to avoid in the first place.
>
> Andreas
>

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026