更新bills(5秒)；利用对bill_items的循环嵌套读取来顺序扫描。
Update bills (5 seconds); sequential scan of bills with a nested loop read of bill_items.
设计形式良好的循环嵌套和流程片断分支，将是降低出现建模错误的可能性的有效方式。
A well-formed nesting of cyclic and branching process fragments is a good approach to reduce the possibility of modeling errors.
分析了预处理循环控制流系统的特点：硬件电路的循环嵌套形式，预处理程序的设计思想。
The characteristics of pretreatment and cyclic control stream are analysed:the form of cyclic embedded hardware circuit, the idea for designing the pretreatment program.
这里使用了嵌套的循环连接方法来连接来自每个仓库的远程查询结果和xml合成视图结果。
The nested loop join method is used to join the remote query result from each warehouse and the XML composite view result.
连接计划指示，强制优化器使用指定的连接方法来连接查询中的表，要么是嵌套循环连接、分类合并连接，要么是动态哈希连接。
Join plan directives that force optimizer to use the designated join method to join tables in the query, either nested loop join, sort merge join, or dynamic hash join.
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)。
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).
如前所述，按顺序的输入对于合并扫描联接是必不可少的，但其无需嵌套循环联接。
As previously stated, ordered input is essential to a merge scan join, but it is not required for nested loop joins.
图4展示了一个在联邦服务器使用嵌套循环连接操作符来计算这个查询的计划。
Figure 4 shows a plan using the nested loop join operations at the federated server to evaluate this query.
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。
This is a lot faster than a nested loop join of two table scans without any index usage.
唯一有趣的是现在是一个嵌套循环。
要了解嵌套循环联接的更多信息，请参考参考资料部分中针对您的DB 2平台的适当的信息中心链接。
For more information about nested loop joins, refer to the appropriate information center link in the Resources section for your DB2 platform.
因此，当与嵌套循环联接比较时，合并扫描联接可能对于排序输入产生成本。
So when compared to a nested loop join, the merge scan join may incur the cost for sorting the inputs.
以我的经验来看，导致程序运行速度慢得罪魁祸首可能就是某个内部或嵌套循环，也可能是对第三方库函数的调用。
In my experience, it will usually be a particular inner or nested loop, or a call to some third party library methods, which is the main culprit for running the program slow.
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。
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.
这种类型的访问路径被称为使用复合排序的嵌套循环联接(NLJOIN)。
This type of access path is referred to as a nested loop join (NLJOIN) with sort composite.
因此，在图7中优化器选择排序嵌套循环联接的复合物。
Therefore, in Figure 7 the optimizer chooses to sort the composite for the nested loop join.
以上示例展示了如何使用连续扫描和索引来进行数据检索，以及如何使用嵌套循环连接方法来连接所有表。
The above example shows that sequential scan and indexes are used to do the data retrieval, and the nested-loop join method is used to join all tables.
然而，合并扫描联接的好处是不必反复地扫描内部表因为其为嵌套循环联接工作。
However, the benefit of the merge scan join is that the inner table does not have to be scanned repeatedly as it does for nested loop joins.
而且，嵌套循环联接方法用于联接源表与目标表。
Also, the nested loop join method is used to join the source and target tables.
最常用的连接方法就是嵌套循环连接、分类合并连接和动态哈希连接。
The most commonly used join methods are nested-loop join, sort merge join and dynamic hash join.
该联接操作的结果就成为第一个联接操作输入到第二个联接操作（也是一个嵌套循环联接）。
The result of that join operation then becomes the first input to the second join operation (also a nested loop join).
执行带有循环(特别是嵌套循环)的方法可能需要耗费很多时间。
Methods with loops, and particularly nested loops, can be time-consuming to execute.
以下是在执行嵌套循环联接的第一步时将发生的操作。
Here's what happens at execution time for the first leg of the nested loop join.
有时候，使用这种语句比嵌套的for循环或if语句更好，可以减少重复的代码而且结构更清楚。
Using such a statement can sometimes be a better route than nested for loops or if statements to cut down on repetitive code or just for better structure.
使用复合排序的嵌套循环联接(NLJOIN)。
因为嵌套循环联接的工作方式，所以每隔一个外部表记录执行第二步(共4个节点)。
Because of how nested loop joins work, the second leg (there are four nodes) is executed per outer table record.
更新bill_items(58秒)；利用对customer的嵌套循环读取，来顺序扫描bill_items。
Update bill_items (58 seconds); sequential scan of bill_items with a nested loop read of customer.
例子5：INLIST改为嵌套循环连接(查询重写)。
QB 1中三个表用嵌套循环(NLJ)连接。
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 ）。
There is a nested loop join (NLJOIN, step 4) of the insert (step 5) to an index scan (IXSCAN, step 7).
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