Re: Doubt about AccessExclusiveLock in ALTER TABLE .. SET ( .. );

On Mon, Apr 6, 2015 at 12:53 AM, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
wrote:
>
> Fabrízio de Royes Mello wrote:
>
> > Ok guys. The attached patch refactor the reloptions adding a new field
> > "lockmode" in "relopt_gen" struct and a new method to determine the
> > required lock level from an option list.
> >
> > We need determine the appropriate lock level for each reloption:
>
> I don't think AccessShareLock is appropriate for any option change. You
> should be using a lock level that's self-conflicting, as a minimum
> requirement, to avoid two processes changing the value concurrently.

What locklevel do you suggest? Maybe ShareLock?

> (I would probably go as far as ensuring that the lock level specified in
> the table DoLockModesConflict() with itself in an Assert somewhere.)
>

If I understood this is to check if the locklevel of the reloption list
don't conflict one each other, is it?

Regards,

--
Fabrízio de Royes Mello
Consultoria/Coaching PostgreSQL
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