Function get_attgenerated

src/backend/utils/cache/lsyscache.c:1062–1079

* get_attgenerated * * Given the relation id and the attribute number, * return the "attgenerated" field from the attribute relation. * * Errors if not found. * * Since not generated is represented by '\0', this can also be used as a * Boolean test. */

 *		Boolean test.
 */
char
get_attgenerated(Oid relid, AttrNumber attnum)
{
	HeapTuple	tp;
	Form_pg_attribute att_tup;
	char		result;

	tp = SearchSysCache2(ATTNUM,
						 ObjectIdGetDatum(relid),
						 Int16GetDatum(attnum));
	if (!HeapTupleIsValid(tp))
		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
			 attnum, relid);
	att_tup = (Form_pg_attribute) GETSTRUCT(tp);
	result = att_tup->attgenerated;
	ReleaseSysCache(tp);
	return result;
}

/*
 * get_atttype