how to kill a transaction

Hi,

I am seeing one entry in MVCC Blocker Transaction.

348,791;hostname;30,001;-1;28;-1;28;115,208;0;ACTIVE;EXTERNAL TRANSACTION;Mar 7, 2016 3:40:39 PM;?;14,697,691;0;0;0;0;0;0;0;1,800,000;0;;0;6,408;0;0;0;0;14,697,691;-1;0;READ COMMITTED;TRUE;TRUE;0;

Connection ID is showing as -1.

can you please help me what to do?

do i need to cancel/kill the session with ID "-1"???

ALTER SYSTEM DISCONNECT SESSION '-1'

will this command work to kill the blocker transaction?

Regards,

Praveen Chanda