Re: memory leak regression 9.1 versus 8.1

Joe Conway <mail@joeconway.com> writes:
> I'm working on an upgrade of PostgreSQL embedded in a product from
> version 8.1.x to 9.1.x. One particular PL/pgSQL function is giving us an
> issue as there seems to be a rather severe regression in memory usage --
> a query that finishes in 8.1 causes an out of memory exception on 9.1.

I see no memory leak at all in this example, either in HEAD or 9.1
branch tip.  Perhaps whatever you're seeing is an already-fixed bug?

Another likely theory is that you've changed settings from the 8.1
installation.  I would expect this example to eat about 10 times
work_mem (due to one tuplestore for each generate_series invocation),
and that's more or less what I see happening here.  A large work_mem
could look like a leak, but it isn't.

If you need further help in debugging, try launching the postmaster
under a fairly restrictive memory ulimit, so that the backend will get a
malloc failure before it starts to swap too badly.  The memory map it
will then print on stderr should point to where the memory is going.
        regards, tom lane