## 查看归档日志使用情况
```sql
sqlplus / as sysdba
select * from v$recovery_file_dest;
select * from V$FLASH_RECOVERY_AREA_USAGE;
```
## 查询日志目录位置
```sql
show parameter recover;
```
## 计算fast_recovery_area已经占用的空间
```sql
select sum(percent_space_used)*3/100 from v$flash_recovery_area_usage;
```
## 修改fast_recovery_aread的空间
```sql
ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE=8g;
```

## rman清理日志
```sql
rman target /
```
## 删除过期归档日志
```sql
crosscheck archivelog all;
delete expired archivelog all;
```
## 删除昨天以前的归档日志
```sql
delete noprompt archivelog until time  'sysdate-1';
```

# 其他
## 显示rman配置
```sql
show all;
```
## 报告目标数据库的物理结构
```sql
report schema;
```
## 报告陈旧备份
```sql
report obsolete;
```
## 报告不可恢复的数据文件
```sql
report unrecoverable;
```
## 列出备份信息
```sql
list backup;
list backup summary;
list backup of database;
list backup of tablespace table_name;
list backup of controlfile;
list backup of spfile;
list backupset id;
```
## 校验备份
```sql
crosscheck backup;
crosscheck backup of database;
crosscheck backup of tablespace system;
crosscheck backup of controlfile;
crosscheck backup of spfile;
crosscheck backup of archivelog all;
```
## 校验没有备份过的归档日志
```sql
crosscheck archivelog all;
delete noprompt expired archivelog all;
```
## 刪除所有的Archivelog files
```sql
delete archivelog all;　
```
## 強制刪除昨天以前的archivelog files
```sql
delete force archivelog until time 'sysdate -1';
delete noprompt  force archivelog until time 'sysdate -2';
```
## 刪除所有过期的Archivelog files
```sql
delete expired archivelog all;
```
##  删除陈旧备份
```sql
delete obsolete;
delete noprompt obsolete;
```
## 删除所有expired的备份（包括归档日志、控制文件、备份聚）
```sql
delete expired backup;
```
## 删除所有备份
```sql
delete backup;
```
## 改为长期备份
```sql
change backupset id unavailable;
change backupset id keep forever logs;
change backupset id keep until time 'sysdate+30' logs;
change backupset id nokeep;
```
## 改为基于时间的备份
```sql
configure retention policy to recovery window of 30 days;
```
## 改为基于冗余数量的备份
```sql
configure retention policy to redundancy  n ;
```
## 取消备份保留策略
```sql
configure retention policy to none;
```
## 设置归档日志存放在其它位置
```sql
set archivelog destination to 'e: emp';
```