Resolving Oracle TNS Errors

  1. In the listener.ora file make sure that service name is included

     

    (SID_DESC =
    (SID_NAME = dbname)
    (ORACLE_HOME = ‘appropriate path’)

     

    )
  2. For the errors
    ORA-12519, TNS:no appropriate service handler found
    The Connection descriptor used by the client was:
    and
    Connection[Listener refused the connection with the following error:
    ORA-12518, TNS:listener could not hand off client connection
    the reason for this is number of processes used by Oracle exceeded the maximum value specified in init ORA parameter
  3. The value of parameter ‘processes‘ can be seen by logging into
    sqlplus database as ‘sqlplus sys/(dbname) as sysdba’
    and then using command ‘show parameter processes’
  4. The value can be edited by
    editing two files init(dbname).ORA and SPFILE(DBNAME).ORA
  5. Then start/stop Windows services for listener and database.
    The modified value can be verified by using step 3