Aidan Van Dyk wrote:
> Would we (ya, the royal we) be willing to say that if you want the
> benifit of removing the MVCC overhead of long-running queries you need
> to run PITR backup/archive recovery, and if you want SR, you get a
> closed-loop master-follows-save-xmin behaviour?
>
To turn that question around a little, I think it's reasonable to say
that closed-loop master-follows-slave-xmin behavior is only practical to
consider implementing with SR--and even there, it should be optional
rather than required until there's more field experience on the whole
thing. Whether it's the default or not could take a bit of debate to
sort out too.
If you think of it in those terms, the idea that "you need to run PITR
backup/archive recovery" to not get that behavior isn't an important
distinction anymore. If you run SR with the option enabled you could
get it, any other setup and you won't.
--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.us
