Note that a DB database is very much like a table in a relational database system in that most DB applications use more than one database (just as most relational databases use more than one table).

• 注意；我们这里的DB数据库和关系数据库中的表十分类似；绝大部分DB应用使用不只一个数据库(正如大部分关系数据库不只一个表).