Error: ORA-03113: end-of-file on communication channel when connecting to Database (40449)

When the user tries to connect to the Database the following error messages are received:

ORA-03113: end-of-file on communication channel

- Click OK, it immediately follows the error message:

ORA-03114: not connected to ORACLE

- Click OK again, same message appears:

ORA-03114: not connected to ORACLE

- Click OK and the messages go away.

SOLUTION 1:

The Oracle DBA applied the 10.2.0.3 patch set and scheduled regular flushes to the Instance on the database, as per Metalink Knowledge Base:

"Implementing regular flushes of the shared pool can prevent the problem from occurring..."

Copy and paste the link to view the entire article:

https://metalink.oracle.com/metalink/plsql/f?p=130:14:11234951658564579228::::p14_database_id,p14_docid,p14_show_header,p14_show_help,p14_black_frame,p14_font:NOT,418531.1,1,1,1,helvetica#DESCRIPTION

Note: Metalink account is required to view Knowledge Base.

User had the following set up:

- Toad for Oracle version 8.0.0.47
- Oracle client version was 10.2.0.2.
- Database Server was 10g Enterprise, 10.2.0.3.0

User upgraded both the Oracle client and Database Server recently but claimed that it was working after upgrade for a while.