ORA-19804 and ORA-19809: Tricked

ORA-19804 and ORA-19809:  are the common errors encountered backing oracle database using RMAN.
The main cause is db_recovery_file_dest_size being exceeded. So we have to free up the db_recovery_file_dest.
We can increase the size of db_recovery_file_dest_size :

sql> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE = 4G SCOPE=BOTH SID='*';

otherwise we keep it as it is, and just free it.

Here are some steps to work around:

1. sql> show parameter db_recovery;
2. sql> select SPACE_USED,SPACE_LIMIT from  v$recovery_file_dest;
3. rman> RMAN CROSSCHECK ARCHIVELOG ALL;
4. rman> change CHANGE ARCHIVELOG ALL VALIDATE;
5. rman> DELETE EXPIRED ARCHIVELOG ALL;
6.  However if after running the previous you receive and unsatisfactory result stating that specification does not match any archived log in the repository. Then you have to blow it away with your following Russian made Anti-patriot Missile command.
7.  rman> delete force archivelog until time 'sysdate -1'; 
8. YES  Enter !
9. Boooooooooommmmmmmmm

So that is it, just the summary to give you few hints. If you still have some problems don't hesitate to throw some comments.