RMAN 删除无效 过期备份

删除无效备份（根据备份策略不需要的）：DELETE OBSOLETE;

删除过期备份（实际已经不存，空有一条记录）：DELETE EXPIRED;

文档如下：

Crosschecks update outdated RMAN repository information about backups whose repository records do not match their physical status.    DELETE EXPIRED;

The RMAN DELETE command supports an OBSOLETE option, which deletes backups that are no longer needed to satisfy specified recoverability requirements. 

删除无效备份前查看下无效的文件：REPORT OBSOLETE;
删除过期备份前要使用CROSSCHECK BACKUP;对记录做检查和标记。

删除无效备份则需要先明确下当前的备份策略：

show retention policy;

改成保留3天的数据。

configure RETENTION POLICY TO recovery window of 3 days;