Re: Lock

Added to TODO.detail lock file.

> On Sat, 18 Dec 1999, Bruce Momjian wrote:
>
> > [Charset ISO-8859-1 unsupported, filtering to ASCII...]
> > > I was looking at this
> > >
> > > * Allow LOCK TABLE tab1, tab2, tab3 so all tables locked in unison
> > >
> > > but I'm not sure if my solution is really what was wanted, because it
> > > doesn't actually guarantee an all-or-nothing lock, it just locks each
> > > table in order. Thus it's more like a syntax simplification and reduces
> > > overhead.
> > >
> >
> > It took a few minutes, but I remember the use for this.  If you are
> > going to hang waiting to lock tab3, you don't want to lock tab1 and tab2
> > while you are waiting for tab3 lock.  The user wanted all tables to lock
> > in one operation without holding locks while waiting to complete all
> > locking.
> >
> > Can you do the locks, and if one fails, not hang, but unlock the
> > previous tables, go lock/hang on the failure, and go back and lock the
> > others? Seems it would have to be some kind of lock/fail/unlock/wait
> > loop.
> >
> > Does this make sense?  It did to me.
>
> Guys, have a look at:
>
> http://www.freebsd.org/~terry/iml.txt
> http://jazz.external.hp.com/training/sqltables/c5s17.html
>
> It's a way to do locking with deadlock detection, and without loosing
> your place in line for locks, very nifty imo.
>
> -Alfred
>
>
> ************
>
>


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