With system administrators, see the current database, there are several users: SQL> Select Username, SID, Serial # from v $ session; if you want to stop a connection SQL> ALTER System Kill session SID, serial #; if this order is not Looking for a UNIX process SQL> SELECT Pro.SPID from V $ Session SES, V $ Process Pro Where ses.SID = 21 and SES.PADDR = Pro.Addr; Description: 21 is a connection to SID Kill command kills this process number.