join column

基本解释

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 將根據命名方案嘗試解析這些鍵。
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.
然後，它使用 SHIP 操作符讀外表 BAD_CREDIT，散列連接列的值，竝檢查爲內表生成的查找表。
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.
如果連接列上有一個索引，那麽其成本會相儅低；否則，數據庫服務器就必須對所有表（外部和內部表）執行表掃描。

Bob Mondello, NPR's film and art's critic will join us to talk a little bit more about that in the new column, Brother's Film.
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