Select operator has zero cost and cardinality

Query:
select count (1) from R, S where int64_default_null (R.rand) /+ productivity R 1.0 */ /+ indexnl / = int64_default_null (S.rand) and R.rand /+ selectivity 0.000244 / <= 1024 and S.rand /+ selectivity 0.000244 */ <= 1024;

One of the select operators in the query plan has zero cost and cardinality.