presto-cassandra/src/main/java/io/prestosql/plugin/cassandra/util/CassandraCqlUtils.java/CassandraCqlUtils/selectDistinctFrom
class CassandraCqlUtils:    public static Select selectDistinctFrom(CassandraTableHandle tableHandle, List<CassandraColumnHandle> columns)
    {
        return from(select(columns).distinct(), tableHandle);
    }