Re: advisory locks and permissions - Mailing list pgsql-hackers

From Jim C. Nasby
Subject Re: advisory locks and permissions
Date
Msg-id 20060922174736.GQ28987@nasby.net
Whole thread Raw
In response to Re: advisory locks and permissions  ("Merlin Moncure" <mmoncure@gmail.com>)
Responses Re: advisory locks and permissions
List pgsql-hackers
On Fri, Sep 22, 2006 at 01:42:48PM -0400, Merlin Moncure wrote:
> On 9/22/06, Jim C. Nasby <jim@nasby.net> wrote:
> >I'm not asking for a defined solution to how to support multiple
> >different users of locks within the same database. I just want us to set
> >aside (as in, recommend they not be used) some set of numbers so that in
> >the future we could recommend a means of picking lock numbers that will
> >avoid collisions.
> 
> you pretty much already have this, current advisory lock exposes 64
> bits of locktag storage.  there is 112 bits (3 int4 and 1 int2)
> available.   this is since 8.1 when locktag was reorganized.  I was
> actually going to suggest esposing these fields but had second
> thoughts due to future proofing issues.
> 
> note i am not arguing that advisory lock should not be expanded in the
> future or do string maps, just that at present talking about reserved
> ranges would just confuse people since the lock space is intentionally
> generic.

Ahh, ok, I didn't realize that the total lock space was larger than
what's being exposed today. That means we can easily add that stuff in
the future and not break anything, which is all I was looking for.
-- 
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)


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