如图8的IXSCAN描述符所示，通过优化器利用的索引的领先列是PRODUCT _ NUMBER，其不为合并扫描联接提供所需的顺序。

As shown in the IXSCAN descriptor in Figure 8, the leading column of the index exploited by optimizer is PRODUCT_NUMBER, which does not provide the order required for merge scan join.

youdao

使用这一简单更改配置文件的方法(在Spring情形中，更改xml描述符)，您可以更改组件的实现方式以使用不同的索引策略。

Using this approach of simply altering a configuration file (in the Spring case, an XML descriptor), you can change the component's implementation to use a different indexing strategy.

youdao

在第二种情况下，文档转换器和索引引擎组件及其子组件通过描述符在外部进行定义，然后使用Spring进行实例化。

In the second scenario, the document translator and indexing engine components and their subcomponents are externally defined through a descriptor and are instantiated using Spring.

youdao