有人叫它数据卫士，有人叫它data guard，在oracle的各项特性中它有着举足轻理的地位,他提供全面的服务包括：创建，维护，管理以及监控standby数据库，确保数据安全，管理员可以通过将一些操作转移到standby数据库执行的方式改善数据库性能-Some people call it Data Guard, some people call it data guard, in the oracle of the characteristics of the reason it has held the position of full light, he provides a comprehensive services include: creation, maintenance, management and monitoring standby databases to ensure data security, management, Members of some operations can be transferred to the standby database, the implementation of ways to improve database performance