So we added indexes on those joining columns and from the following query execution plan, we can see the query cost is greatly reduced.
因此，我们在这些连接列上添加了索引，从下列查询执行计划中我们可以看到，查询成本减少了很多。
Though we did not sort this list, we immediately can see the query with the highest execution time is 41.844554.
虽然我们没有排序该列表，但可以立即看到具有最高执行时间的查询是41.844554。
In Figure 2, you see three different execution plans for this query (simplified output from db2exfmt).
在图2中可以看到该查询的不同执行计划(简化了db 2 exfmt的输出)。
Also as shown in Figure 11, you can see that there are still two table scans for each execution of the query.
还是如图11所示，每次执行查询都有两个表扫描。
Also as shown in Figure 11, you can see that there are still two table scans for each execution of the query.
还是如图11所示，每次执行查询都有两个表扫描。
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