Make pg_get_statisticsobjdef_expressions return NULL
The usual behavior for functions in ruleutils.c is to return NULL when
the object does not exist. pg_get_statisticsobjdef_expressions raised an
error instead, so correct that.
Reported-by: Justin Pryzby
Discussion:
@@ -1759,9 +1759,9 @@ pg_get_statisticsobjdef_expressions(PG_FUNCTION_ARGS)
statexttup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(statextid));
if (!HeapTupleIsValid(statexttup))
- elog(ERROR, "cache lookup failed for statistics object %u", statextid);
+ PG_RETURN_NULL();
- /* has the statistics expressions? */
+ /* Does the stats object have expressions? */
has_exprs = !heap_attisnull(statexttup, Anum_pg_statistic_ext_stxexprs, NULL);
/* no expressions? we're done */
