flink sql lookup join中维表不可以是视图吗？

lookup join用的维表需要从两张mysql表做关联后得到，因此创建了一个视图。但发现flink sql不支持lookup join关联视图，会抛 Temporal Table Join requires primary key in versioned table, but no primary key can be found.

请问这种情况要怎么解决？

CREATE VIEW query_mer_view (mer_cust_id, update_time) AS SELECT a.mer_cust_id, k.update_time FROM ka_mer_info k INNER JOIN adp_mer_user_info a on k.mer_cust_id = a.mer_cust_id where k.mer_cust_id <> '';

SELECT DATE_FORMAT(c.create_time, 'yyyy-MM-dd') AS payment_date, c.mer_cust_id,

c.trans_amt, CASE c.trans_stat WHEN 'S' THEN c.trans_amt ELSE 0 END as succ_amt ,

1 as trans_cnt, CASE c.trans_stat WHEN 'S' THEN 1 ELSE 0 END as succ_cnt , CASE c.trans_stat WHEN 'F' THEN 1 ELSE 0 END as fail_cnt

FROM charge_log as c LEFT JOIN query_mer_view FOR SYSTEM_TIME AS OF c.proc_time AS q ON c.mer_cust_id = q.mer_cust_id;*来自志愿者整理的flink