server crash on recursive function invocation

Ali Baba said:

hi,
i was just trying recursive function invocation and got a server crash
when i changed a GUC variable max_stack_depth, to a high number.
fallowing is what i have tried.

select max_val from pg_settings where name='max_stack_depth'; --
returns 2097151 set max_stack_depth=2097151;
CREATE OR REPLACE FUNCTION func() RETURNS INT AS $$
DECLARE
x int;
BEGIN
null;
x := func();
return 0;
END;
$$ LANGUAGE PLPGSQL;
select func();
and the server get crashed.

Any ideas?

what the heck did you expect with an infinitely recursive function?

cheers

andrew

Ali Baba <idofyear@yahoo.com> writes:

i was just trying recursive function invocation and got a server crash when i changed a GUC variable max_stack_depth, to a high number.

There's a reason why that variable is a superuser-only setting: you're
supposed to have some clue what you're doing when you change it ;-)

If you need more stack space, what you generally have to do is adjust
the ulimit setting that the postmaster is started under. You can set
max_stack_depth up to a few hundred K less than the postmaster's
ulimit -s setting, but not more.

(We wouldn't even have the variable if there were a sufficiently
portable way to find out the ulimit stack depth automatically, but
there's not one that I know of.)

regards, tom lane