RMAN - unregister not existed database from catalog

Normally when I tried unregister non-existed database in RMAN catalog I received error:

execute dbms_rcvcat.unregisterdatabase(818673443,879389610);
BEGIN dbms_rcvcat.unregisterdatabase(818673443,879389610); END;

*
ERROR at line 1:
ORA-02292: integrity constraint (RMAN.TSATT_F2) violated - child record found
ORA-06512: at "RMAN.DBMS_RCV

Probably some informations about backups are still in catalog for this database but without database I can't unregister this datbase.

Solution:

select name,DB_KEY,DBINC_KEY,dbid from rman.rc_database where name=<database_name>;
delete rman.tsatt where DBINC_KEY=<DBINC_KEY for db>;

commit;

execute dbms_rcvcat.unregisterdatabase(<DB_KEY for db>,<DBID for db>);

PL/SQL procedure successfully completed.