Jeff Janes <jeff.janes@gmail.com> writes:
> I had a perhaps crazier idea. Aren't CLOG pages older than global xmin
> effectively read only? Could backends that need these bypass locking
> and shared memory altogether?
Hmm ... once they've been written out from the SLRU arena, yes. In fact
you don't need to go back as far as global xmin --- *any* valid xmin is
a sufficient boundary point. The only real problem is to know whether
the data's been written out from the shared area yet.
This idea has potential. I like it better than Robert's, mainly because
I do not want to see us put something in place that would lead people to
try to avoid rollbacks.
regards, tom lane