首页 > Linux操作系统 > Linux操作系统 > [zt] 10gR2 rman对Unused Block Compression

[zt] 10gR2 rman对Unused Block Compression

原创 Linux操作系统 作者:tolywang 时间:2009-02-12 16:03:00 0 删除 编辑



rman>backup full database format = 'd:test.bak';


Unused Block Compression Of Datafile Backups to Backup Sets
When backing up datafiles into backup sets, RMAN does not back up the contents of data blocks that have never been allocated. (In previous releases, this behavior. was referred to as NULL compression.)
RMAN also skips other datafile blocks that do not currently contain data, if all of the following conditions apply:
■ The COMPATIBLE initialization parameter is set to 10.2
■ There are currently no guaranteed restore points defined for the database
■ The datafile is locally managed
■ The datafile is being backed up to a backup set as part of a full backup or a level 0 incremental backup
■ The backup set is being created on disk.
Skipping unused data blocks where possible enables RMAN to back up datafiles using less space, and can make I/O more efficient. 


来自 “ ITPUB博客 ” ,链接:,如需转载,请注明出处,否则将追究法律责任。

请登录后发表评论 登录
Oracle , MySQL, SAP IQ, SAP HANA, PostgreSQL, Tableau 技术讨论,希望在这里一起分享知识,讨论技术,畅谈人生 。


  • 博文量
  • 访问量