Alan,
> You need to be careful using Alan's patch. The reason RH stopped using
> this part of it in their errata kernels is that it had conflicts with
> other stuff, specifically the rmap stuff (he told me that himself in
> email).
Hmmm ... that leaves us without a workaround for this problem, then, yes?
Because even parnoid-mode kernels you can discourage, but not prevent,
overcommitting.
> For mission critical apps I would advise running the postmaster on a
> dedicated machine, with no X or other nasty stuff running.
Unfortunately, this is frequently not an option ... PostgreSQL is often
together on a server with Apache, a JVM, and other server software. As
happened in the one case of possible (diagnosis pending) failure that we are
looking into. Of course, it could be something else ....
--
Josh Berkus
Aglio Database Solutions
San Francisco