An index requires a source (that is, a set of rows) and defines how the data extracted from the source should be cataloged.

index将要求获得数据源(即一组数据行)并定义应当如何为已从数据源中提取出来的数据编目。

youdao

An index requires a source (that is, a set of rows) and defines how the data extracted from the source should be cataloged.

index将要求获得数据源(即一组数据行)并定义应当如何为已从数据源中提取出来的数据编目。

youdao