In the previous section you learned about one type of access method, index scan (IXSCAN), and one type of join method, nested loop join (NLJOIN).

在之前的部分您已经了解了一种类型的访问方法，即索引扫描(IXSCAN)，和一种类型的联接方法，即嵌套循环联接(NLJOIN)。

youdao

This is a lot faster than a nested loop join of two table scans without any index usage.

这比不使用任何索引的两个表扫描的嵌套循环连接要快得多。

youdao

In general, a nested loop join with sort composite is favored by the optimizer if the inner index is well-clustered and the inner table is expected to be probed many times.

一般来说，如果内部索引是良好的集群且预测内部表被多次探测，则使用复合排序的嵌套循环联将受到优化器的青睐。

youdao

There is a nested loop join (NLJOIN, step 4) of the insert (step 5) to an index scan (IXSCAN, step 7).

其中有一个insert（步骤5）与索引扫描（步骤7）之间的嵌套循环连接（NLJOIN，步骤4 ）。

youdao

There is a nested loop join (NLJOIN, step 4) of the insert (step 5) to an index scan (IXSCAN, step 7).

其中有一个insert（步骤5）与索引扫描（步骤7）之间的嵌套循环连接（NLJOIN，步骤4 ）。

youdao