ORA- 03113  end-of-file on communication channel
Cause: An unexpected end-of-file was processed on the communication channel. The problem could not be handled by the Net8, two task, software. This message 
could occur if the shadow two-task process associated with a Net8 connect has terminated abnormally, or if there is a physical failure of the interprocess communication 
vehicle, that is, the network or server machine went down. In addition, this message could occur when ALTER SYSTEM KILL SESSION or ALTER SYSTEM 
DISCONNECT SESSION were issued with the IMMEDIATE qualifier because, in those cases, the client's connection to the database is terminated without waiting for 
the client to issue a request.
Action: If this message occurs during a connection attempt, check the setup files for the appropriate Net8 driver and confirm Net8 software is correctly installed on the 
server. If the message occurs after a connection is well established, and the error is not due to a physical failure, check if a trace file was generated on the server at 
failure time. Existence of a trace file may suggest an Oracle internal error that requires the assistance of customer support. 
ORA-03114 not connected to ORACLE
Cause: A call to Oracle was attempted when no connection was established. Usually this happens because a user-written program has not logged on. It may happen if 
communication trouble causes a disconnection. In addition, this message could occur when ALTER SYSTEM KILL SESSION or ALTER SYSTEM DISCONNECT 
SESSION were issued with the IMMEDIATE qualifier because, in those cases, the client's connection to the database is terminated without waiting for the client to issue 
a request.
Action: Try again. If the message recurs and the program is user written, check the program.