Re: LWLockAcquire and LockBuffer mode argument

Hi,

On 2020-08-25 13:59:35 -0400, Robert Haas wrote:
> On Mon, Aug 24, 2020 at 6:35 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
> > Thoughts?
>
> This is likely to cause a certain amount of annoyance to many
> PostgreSQL developers, but if you have evidence that it will improve
> performance significantly, I think it's very reasonable to do it
> anyway.

I don't think it'll be a "significant" performance benefit directly. It
appears to be measurable, but I think to reach significant performance
improvements it'll take a while and it'll come from profilers and other
tools working better.

> However, if we do it all in a backward-compatible way as you propose,
> then we're likely to keep reintroducing code that does it the old way
> for a really long time. I'm not sure that actually makes a lot of
> sense. It might be better to just bite the bullet and make a hard
> break.

It seems easy enough to slap a compiler "enforced" deprecation warning
on the new compat version, in master only. Seems unnecessary to make
life immediately harder for extensions authors desiring cross-version
compatibility.

Greetings,

Andres Freund