Incremental Backup: 2 个级别,level 0 和level 1, 0 级备份包含数据文件中所有block,1 级备份改变的block,执行增量备份的时候,要先做0 级备份,作为增量备份的基础.
(1)An INCREMENTAL backup at level 0 backs up all data blocks in datafiles being backed up.
(2)A level 1 backup copies only changed blocks. A level 1 incremental backup is either differential or CUMULATIVE. If cumulative, RMAN backs up all blocks changed since the most recent level 0 backup. If differential, RMAN backs up blocks updated since the most recent level 0 or level 1 incremental backup.
A backup strategy as follows:
1. On Sunday, an incremental level 0 tape backup is performed
2. Monday through Saturday, a cumulative incremental level 1 tape backup is performed
A. The backup performed in step 1 backs up all blocks that have ever been in use in the database
B. The backup performed in step 2 copies all the blocks changed since the most recent level 0 backup
增量备份分2 类:
差异增量:包含上次增量备份以来更改的所有块,默认增量备份方式;
累积增量:包含上次级别为0 的增量备份以来更改的所有块.
