Si no han hecho spfile:
create spfile from pfile;
shutdown immediate;
startup;
show parameter spfile;
Luego se puede configurar el tamaño del recovery:
SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE = 10G SCOPE=BOTH SID='*';
y checar:
SELECT * FROM V$RECOVERY_FILE_DEST;
SELECT * FROM V$FLASH_RECOVERY_AREA_USAGE;
elige el recovery window:
RMAN> CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;