This tells me that I may have an inefficient access path, where DB2 reads more data than it should.

这就说明我可能有一个低效的访问路径，DB 2读取的数据比应该读取的数据更多。

youdao

Optimized for one problem: By their nature, hierarchical databases optimized access to the data through one specific path.

针对单个问题的优化：本质上，层次数据库就通过一条指定的路径来优化数据访问。

youdao

In addition, the database can have a better understanding of the state of the data it stores, and thereby can produce a more efficient and dynamic access path to the data.

此外，数据库可以更好地理解它存储的数据的状态，从而可以生成到数据的更有效和动态的存取路径。

youdao