Re: [HACKERS] Moving relation extension locks out of heavyweight lock manager

Hi,

On 2020-02-19 11:12:18 +0530, Amit Kapila wrote:
> I think till we know the real need for changing group locking, going
> in the direction of what Tom suggested to use an array of LWLocks [1]
> to address the problems in hand is a good idea.

-many

I think that building yet another locking subsystem is the entirely
wrong idea - especially when there's imo no convincing architectural
reasons to do so.

> It is not very clear to me that are we thinking to give up on Tom's
> idea [1] and change group locking even though it is not clear or at
> least nobody has proposed an idea/patch which requires that? Or are
> we thinking that we can do what Tom suggested for relation extension
> lock and also plan to change group locking for future parallel
> operations that might require it?

What I'm advocating is that extension locks should continue to go
through lock.c. And yes, that requires some changes to group locking,
but I still don't see why they'd be complicated. And if there's concerns
about the cost of lock.c, I outlined a pretty long list of improvements
that'll help everyone, and I showed that the locking itself isn't
actually a large fraction of the scalability issues that extension has.

Regards,

Andres