ORA-19809 & ORA-19804

19804, 00000, "cannot reclaim %s bytes disk space from %s limit"
// *Cause: Oracle cannot reclaim disk space of specified bytes from the
//         DB_RECOVERY_FILE_DEST_SIZE limit.
// *Action: There are five possible solutions:
//          1) Take frequent backup of recovery area using RMAN.
//          2) Consider changing RMAN retention policy.
//          3) Consider changing RMAN archived log deletion policy.
//          4) Add disk space and increase DB_RECOVERY_FILE_DEST_SIZE.
//          5) Delete files from recovery area using RMAN.

19809, 00000, "limit exceeded for recovery files"
//*Cause: The limit for recovery files specified by the
//        DB_RECOVERY_FILE_DEST_SIZE was exceeded.
// *Action: There are five possible solutions:
//          1) Take frequent backup of recovery area using RMAN.
//          2) Consider changing RMAN retention policy.
//          3) Consider changing RMAN archived log deletion policy.
//          4) Add disk space and increase DB_RECOVERY_FILE_DEST_SIZE.
//          5) Delete files from recovery area using RMAN.

19804, 00000，“无法从%s限制中回收%s字节的磁盘空间”

//*原因：Oracle无法从数据库中回收指定字节的磁盘空间

//数据库恢复文件目标大小限制。

//*行动：有五种可能的解决方案：

//1）使用RMAN对恢复区域进行频繁备份。

//2）考虑更改RMAN保留策略。

//3）考虑更改RMAN归档日志删除策略。

//4）增加磁盘空间并增加DB_RECOVERY_FILE_DEST_大小。

//5）使用RMAN从恢复区域删除文件。

show parameter db_recovery_file_dest;


alter system set db_recovery_file_dest_size=20g scope=both;

backup as compressed backupset database format '+SSDDG1/baipx/baipx_full_%d_%s' plus archivelog;

BACKUP AS COMPRESSED BACKUPSET DATABASE;

1. 备份和还原的时候的压缩和解压缩，是由RMAN完成的，不需要额外的过程。
2. compressed参数只对备份集进行压缩，image copy 不能使用该参数。image copy就是copy原始的文件。原始的文件多大，image copy就多大。
3. 二进制压缩在备份和还原操作期间会产生一些性能开销。会消耗CPU。降低带宽的使用率。