PURGE DBA_RECYCLEBIN command empties the recyclebin at database level i.e. purges the recyclebin for all users in the database. Until 11g , you need to have powerful
SYSDBA system privilege to execute this command. To some extent it made sense as this option was mainly used for upgrades or migration or to apply DST patch. One of focus areas of Oracle12c is separation of duties resulting in new roles like SYSKM for wallet management, SYSBACKUP for backups and restore, SYSDG for administration of Data Guard.
Along the same lines, We have new privilege PURGE DBA_RECYCLEBIN that helps with implementing separation of duty. Users granted the PURGE DBA_RECYCLEBIN system privilege can purge the recyclebin for all users in the database using the PURGE DBA_RECYCLEBIN command.