如果查询中有属于多列索引的连接列或过滤列,则使用UPDATE STATISTICS HIGH。
Use UPDATE STATISTICS HIGH if queries have a multi-column indexed defined on join columns or filter columns.
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。
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.
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。
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.
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