(2010/06/04 13:57), Tom Lane wrote:
> KaiGai Kohei<kaigai@ak.jp.nec.com> writes:
>> (2010/06/04 11:55), Robert Haas wrote:
>>> A (very) important part of this problem is determining which quals are
>>> safe to push down.
>>>
>> At least, I don't have an idea to distinguish trusted functions from
>> others without any additional hints, because we support variable kind
>> of PL languages. :(
>
> The proposal some time back in this thread was to trust all built-in
> functions and no others. That's a bit simplistic, no doubt, but it
> seems to me to largely solve the performance problem and to do so with
> minimal effort. When and if you get to a solution that's committable
> with respect to everything else, it might be time to think about
> more flexible answers to that particular point.
>
Although I've not check all the functions within pg_proc.h, it seems to
me reasonable assumptions, except for a small number of exception which
have side-effects, such as lo_write().
Maybe, we have to shut out a small number of exceptions.
However, at least, it seems to me reasonable assumption in this stage.
Thanks,
--
KaiGai Kohei <kaigai@ak.jp.nec.com>
