Inheritance is limited: with ActiveRecord, I'm forced to use a mapping strategy called single table inheritance (see Resources), which is not always optimal.
The disk subsystem is organized for optimal performance by carefully mapping the tablespaces onto the disks.
还要通过仔细地将表空间映射到磁盘上来组织好磁盘子系统，从而获得最佳性能。
3
Using this mapping image can visually eliminate abnormal sample data, select decision variables and predict optimal operating point and direction for an industrial process.