现有环境不用compressed 的主要原因应该是影响性能，同样26GB的database，不用compressed 1分钟备完，用了compressed 需要8-10分钟才能备完。
RMAN> backup DATABASE plus ARCHIVELOG;
Starting backup at 2023-10-31 18:24:21
Finished Control File and SPFILE Autobackup at 2023-10-31 18:25:03
---42秒
RMAN> backup as compressed backupset DATABASE plus ARCHIVELOG;
Starting backup at 2023-10-31 18:27:54
Finished Control File and SPFILE Autobackup at 2023-10-31 18:35:34
--8分钟
RMAN> backup as compressed backupset DATABASE plus ARCHIVELOG;
Starting backup at 2023-10-31 18:39:18
Finished Control File and SPFILE Autobackup at 2023-10-31 18:49:12
--10分钟
RMAN> backup DATABASE plus ARCHIVELOG;
Starting backup at 2023-10-31 18:49:47
Finished Control File and SPFILE Autobackup at 2023-10-31 18:50:42
--55秒
开启16 并行 4分钟 8并行 6分钟，但是CPU core消耗全部90%。
CONFIGURE DEVICE TYPE DISK PARALLELISM 16 BACKUP TYPE TO BACKUPSET;
RMAN> backup as compressed backupset DATABASE plus ARCHIVELOG;
Starting backup at 2023-10-31 19:05:01
Finished Control File and SPFILE Autobackup at 2023-10-31 19:09:07
--4分钟
RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 8 BACKUP TYPE TO BACKUPSET;
RMAN> backup as compressed backupset DATABASE plus ARCHIVELOG;
Starting backup at 2023-10-31 19:10:11
Finished Control File and SPFILE Autobackup at 2023-10-31 19:16:45
--6分钟