ORA-19815: WARNING: db_recovery_file_dest_size of nnn bytes is 100% used

When you get ORA-19815

+ Check if the RMAN is taking the Archive log back properly and deleting the absolute files.

+ Even-though if you have available space at the OS level and SIZE restricted from DB parameter ( db_recovery_file_dest_size ) then we will hit the issue.

+ Also check for available space at the OS level and release the space constraints from the diag location.

If you try to open the DB it will errored out:

SQL> alter database mount;

alter database mount

*

ERROR at line 1:

ORA-01034: ORACLE not available

Process ID: 0

Session ID: 0 Serial number: 0

SQL> shutdown immediate

SQL> startup mount