The join is performed by scanning the inner table of the hash join, CUSTOMERS, and generating a lookup table by hashing the join column values.
该连接的执行过程包括扫描散列连接中的内表CUSTOMERS，并通过散列连接列的值生成一个查找表。
IT then reads from the outer table BAD_CREDIT using the SHIP operator, hashing the join column values, and checking in the lookup table generated for the inner table.
然后，它使用SHIP操作符读外表BAD_CREDIT，散列连接列的值，并检查为内表生成的查找表。
If there is an index on the join column, the costs will be significantly less; otherwise the database server must perform table scans for all tables, both outer and inner tables.
如果连接列上有一个索引，那么其成本会相当低；否则，数据库服务器就必须对所有表(外部和内部表)执行表扫描。
If you do not specify the Join column, JPA will attempt to resolve the keys based on a naming scheme.
如果您未指定join列，JPA将根据命名方案尝试解析这些键。
If you do not specify the Join column, JPA will attempt to resolve the keys based on a naming scheme.
如果您未指定join列，JPA将根据命名方案尝试解析这些键。
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