"Dave Page" <dpage@vale-housing.co.uk> writes:
> ... what about adding a GUC variable that can be used to specify an
> amount of shared memory to use as a fifo area in which a copy of the log
> output is stored for return to clients that might want it (accessing it
> via internal functions)?
No, that's a nonstarter, because having the postmaster log into shared
memory means that the postmaster probably goes down too anytime a
backend crashes. The shared area would have to have a mutual-exclusion
lock, and we definitely do not want the postmaster participating in any
lock protocols.
If I were trying to solve Andreas' problem, I'd pipe stderr to some
program that stores recent log output in a file that I know the location
of and can read from the hypothetical log-grabber function. Actually I
don't see that there's any need to involve Postgres itself in this issue
at all --- seems like the only agreement needed is between the GUI and
the postmaster launching script about where the log file is.
regards, tom lane