Re: PATCH to allow concurrent VACUUMs to not lock each

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> Tom Lane wrote:
>> Knew I should have taken time to review that patch before it went in ...

> Which one? The one I applied doesn't have this change.

Never mind --- I misunderstood the context of the discussion and thought
you had made larger changes in the last version of the patch than I was
expecting ...

The patch as committed looks fine to me, modulo a couple of comments
which I've fixed.

One thing that slightly troubles me is that GetOldestXmin will now
ignore a lazy vacuum's *own* xmin, which is not like the previous
behavior. Offhand I can't see a reason why this is not safe, but
maybe it'd have been better for it to do

+ if (ignoreVacuum && proc->inVacuum && proc != MyProc)
+ continue;

Thoughts?

regards, tom lane