Tatsuo suggested...
> Or even better, MaxBackendId can be set at the run time such as
> postmaster's option. Also, it would be nice if we could monitor number
> of backends currently running. Maybe we should have a new protocol for
> this kind of puropose?
Oracle does this with pseudo-tables. There are about (from my memory)
15 tables, all starting with v$, that let you look into the internals
of a running oracle database. Things like mounted tablespaces, locks,
all sorts of things. One is (I think) just a name,value table for
misc parameters. There were even things like writes/second and
reads/second for performance tuning.
We did a bunch of nice tk front ends for monitoring oracle simply
by looking at the v$ tables.
Using a tables like this (pg_config, pg_backends, pg_transactions,
whatever) would be one way to provide this information.
I haven't delved into backend code enough to know if this
is possible.
-- cary