Обсуждение: Determine a function's volatility in C

Hey all,

I'm wondering if there is a way to determine a function's volatility
in C.  The function information provided through fmgr_info() doesn't
provide it.  Ideas?

Thanks,
Bborie

--
Bborie Park
Programmer
Center for Vectorborne Diseases
UC Davis
530-752-8380
bkpark@ucdavis.edu

Hello

2011/11/12 Bborie Park <bkpark@ucdavis.edu>:
> Hey all,
>
> I'm wondering if there is a way to determine a function's volatility
> in C.  The function information provided through fmgr_info() doesn't
> provide it.  Ideas?
>

you should to look to pg_proc table

search in postgresql code

         tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
        if (!HeapTupleIsValid(tuple))
                elog(ERROR, "cache lookup failed for function %u", funcoid);
        proc = (Form_pg_proc) GETSTRUCT(tuple);

 ...


        switch (proc->provolatile)
        {
                case PROVOLATILE_IMMUTABLE:
                        appendStringInfoString(&buf, " IMMUTABLE");
                        break;
                case PROVOLATILE_STABLE:
                        appendStringInfoString(&buf, " STABLE");
                        break;
                case PROVOLATILE_VOLATILE:
                        break;
        }

...

        ReleaseSysCache(tuple);

Regards

Pavel Stehule


> Thanks,
> Bborie
>
> --
> Bborie Park
> Programmer
> Center for Vectorborne Diseases
> UC Davis
> 530-752-8380
> bkpark@ucdavis.edu
>
> --
> Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-general
>

Bborie Park <bkpark@ucdavis.edu> writes:
> I'm wondering if there is a way to determine a function's volatility
> in C.  The function information provided through fmgr_info() doesn't
> provide it.  Ideas?

extern char func_volatile(Oid funcid)

(Most catalog-lookup convenience functions of this ilk can be found in
lsyscache.c, and that's also a good source of prototypes if you need a
field that's not exposed by one of those functions.)

            regards, tom lane