Dave Potts <dave(dot)potts(at)pinan(dot)co(dot)uk> writes:
> I have just inherited a private C module that lives in the context of
> the server with little or no documentation.
> It crashes taking the database down, is there any advice on how to
> debug this type of beast ?
It isn't a lot different from debugging code that's part of the core
server. You might start with the advice here:
http://wiki.postgresql.org/wiki/Getting_a_stack_trace_of_a_running_PostgreSQL_backend_on_Linux/BSD
(there's a neighboring page for Windows, too)
regards, tom lane