Rod Taylor <rbt@zort.ca> writes:
> Perhaps I'm not remembering correctly, but don't SQL functions still
> have an abnormally high cost of execution compared to plpgsql?
> Want to try the same thing with a plpgsql function?
Actually, plpgsql is pretty expensive too. The thing to be benchmarking
is applications of plain old built-in-C functions and operators.
Also, there are two components that I'd be worried about: one is the
parser's costs of operator/function lookup, and the other is runtime
overhead. Runtime overhead is most likely concentrated in the fmgr.c
interface functions, which tend to do MemSets to zero out function
call records. I had had a todo item to eliminate the memset in favor
of just zeroing what needs to be zeroed, at least in the one- and two-
argument cases which are the most heavily trod code paths. This will
become significantly more important if FUNC_MAX_ARGS increases.
regards, tom lane
