Re: Publish autovacuum informations

2014-12-29 17:03 GMT+01:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Guillaume Lelarge <guillaume(at)lelarge(dot)info> writes:
> > All in all, I want to get informations that are typically stored in
> shared
> > memory, handled by the autovacuum launcher and autovacuum workers. I
> first
> > thought I could get that by writing some C functions embedded in an
> > extension. But it doesn't seem to me I can access this part of the shared
> > memory from a C function. If I'm wrong, I'd love to get a pointer on how
> to
> > do this.
>
> > Otherwise, I wonder what would be more welcome: making the shared memory
> > structs handles available outside of the autovacuum processes (and then
> > build an extension to decode the informations I need), or adding
> functions
> > in core to get access to this information (in that case, no need for an
> > extension)?
>
> Either one of those approaches would cripple our freedom to change those
> data structures; which we've done repeatedly in the past and will surely
> want to do again. So I'm pretty much -1 on exposing them.
>
>
I don't see how that's going to deny us the right to change any structs. If
they are in-core functions, we'll just have to update them. If they are
extension functions, then the developer of those functions would simply
need to update his code.

--
Guillaume.
http://blog.guillaume.lelarge.info
http://www.dalibo.com