Performing Oracle database upgrade

Upgrade Oracle database server from Oracle 12c to Oracle 18c.

Ensure the following are met before you begin the Oracle upgrade procedure.
  • Log in as oracle user and connect to SQL*Plus as sysdba user and run the following query:
    $ export ORACLE_SID=vtdb

$ sqlplus "/ as sysdba"

SQL*Plus: Release 12.1.0.2 Production on Wed Jun 12 19:50:37 2013

Copyright (c) 1982, 2014, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning option

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
PL/SQL Release 12.1.0.2.0 - Production
CORE    12.1.0.2.0      Production
TNS for Linux: Version 12.1.0.2.0 - Production
NLSRTL Version 12.1.0.2.0 - Production

SQL> exit
    The output shows the current version of Oracle that you are running.
  • Oracle recommends a full cold backup of your database.
  • Make sure all the required operating system packages and patches are installed on your system