1,Simple Recovery 模式
Simple Recovery(简单恢复)模式是最容易实现的恢复模式,这种恢复模式本质上与在 sql Server 7.0 中选择 trunc.log on checkpoint 选项相同。Simple Recovery 模式定期截断事务日志,删除已经被提交的所有事务。因为日志经常被截断,所以不能备份。这就使得备份策略只能采用完全备份和差异备份。如果数据库已经配置为 Simple Recovery 模式,那么在试图执行事务日志备份时将接收到错误:
@H_301_4@Server: Msg 4208,Level 16,State 1,Line 1 The statement BACKUP LOG is not allowed while the recovery model is SIMPLE. Use BACKUP DATABASE or change the recovery model using ALTER DATABASE. Server: Msg 3013,Line 1 BACKUP LOG is terminating abnormally.