Unnecessary columns should not be included in the partitioning key.
分区键中不应该包括不必要的列。
In my two previous columns, I wrote about unnecessary SQL and gave examples of SQL that is executed far too many times and SQL that should be replaced with newer, better-performing SQL.
在前面两个专栏中，谈到不必要的SQL，并给出了执行次数过多的SQL例子，以及应当由更新的、性能更优的SQL来替代的例子。
The pros include compact tables (no unnecessary nullable columns), data partitions across three subclass tables and easy association with other tables using the top super class table.
优点包括数据表比较紧凑(没有不需要的可空字段)，数据跨三个子类的表进行分区，容易使用超类的表与其他表进行关联。
应用推荐