How to detect and cleanup pending transactions in Oracle

Usually pending transactions clear up on their own. If not, read on.
　　 If you have a pending transaction that will not go away then check the pending states with the following query:
　　 SELECT local_tran_id, state, mixed
　　 FROM dba_2pc_pending;
　　 Pending transactions can be in any of the following states :
　　 collecting, committed, prepared, forced commit, forced rollback
　　 If the transaction is in the ‘prepared’ state then run
　　 COMMIT FORCE ‘’;
　　 or
　　 ROLLBACK FORCE ‘’;
　　 If the transaction is any state (other than ‘prepared’) and the transaction is not resolving then Log in as ‘SYS’ and run the following script
　　 exec dbms_transaction.purge_lost_db_entry();