Re: Need help understanding pg_locks

Tom Lane wrote:
> Florian Pflug <fgp(at)phlo(dot)org> writes:
> > On Jul11, 2011, at 17:11 , Tom Lane wrote:
> >> Yeah, I think this patch is going in the wrong direction altogether.
> >> It would be better to modify the description of virtualtransaction
> >> and pid to say that those are the "locking" entity.
>
> > Hm, we already kinda of say that. Both descriptions include the phrase
> > "... holding or awaiting this lock.". The column "mode" says
> > "... held or desired by this process", which I guess is similar enough
> > to make it clear that these are related.
>
> > Its the columns which refer to the locked object which simply say
> > "object", and thus leave it open if that means locked or a locking.
>
> > Could we split that table in two parts, one for the fields referring
> > to the locked object and one for the locking entity, or does that depart
> > too far from the way we document other system catalogs and views?
>
> Then you'd have to join them, which would not be an improvement from
> anybody's standpoint.
>
> Maybe we could just add a paragraph above the "pg_locks Columns" table
> that says explicitly that virtualtransaction and pid describe the entity
> holding or awaiting the lock, and the others describe the object being
> locked? Any way you slice it, putting this information into the
> per-column table is going to be repetitive.

Frankly, whenever anyone says "object", they might as well call it
"thing". It seems to be a content-less word. Maybe just replace the
word "object" with "lock".

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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