Determine a function's volatility in C

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

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