After backing up the database that you want to upgrade, prepare the new Oracle home in a new location. Install the software for Oracle Database 12c into the new location.

1. Copy configuration files from the Oracle home of the database being upgraded to the new Oracle home for Oracle Database 12c. If you are using DBUA, the configuration files are copied for you automatically and you can ignore this step.

   If you need to manually copy your configuration files to the new Oracle home:

   1. If your parameter file resides within the old environment's Oracle home, then copy it to the new Oracle home. By default, Oracle looks for the parameter file in the ORACLE_HOME/dbs directory on Linux or UNIX platforms and in the ORACLE_HOME\database directory on Windows operating systems. The parameter file can reside anywhere, but it must not reside in the Oracle home of the old environment after you upgrade to Oracle Database 12c.

      Note:

      You may need to create a text initialization parameter file (PFILE) from the server parameter file (SPFILE) so that you can edit the initialization parameters.

   2. If your parameter file resides within an Oracle ASM instance, then back up the parameter file using the following command:

      CREATE pfile FROM spfile;
      

      If you must downgrade the database and your SPFILE resided within Oracle ASM, then you must restore the parameter file before the downgrade.

   3. If your parameter file is a text-based initialization parameter file with either an IFILE (include file) or a SPFILE (server parameter file) entry, and the file specified in the IFILE or SPFILE entry resides within the old environment's Oracle home, then copy the file specified by the IFILE or SPFILE entry to the new Oracle home. The file specified in the IFILE or SPFILE entry contains additional initialization parameters.

   4. If you have a password file that resides within the old environment's Oracle home, then move or copy the password file to the new Oracle home in Oracle Database 12c.

      The name and location of the password file are operating system-specific. On Linux or UNIX platforms, the default password file is orapwSID, located in the ORACLE_HOME/dbs directory. On Windows operating systems, the default password file is pwdSID.ora, located in the ORACLE_HOME\database directory. In both cases, SID is your Oracle instance ID.

2. Adjust your parameter file in Oracle Database 12c by completing the following steps:

   1. Remove desupported initialization parameters and adjust deprecated initialization parameters. Certain parameters are desupported in Oracle Database 12c, while other parameters have become deprecated. Remove all desupported parameters from any parameter file that starts an Oracle Database 12c instance. Desupported parameters might cause errors in Oracle Database 12c. Also, alter any parameter whose syntax has changed in the new release.

      The Pre-Upgrade Information Tool displays any deprecated parameters and desupported parameters it finds in the Deprecated Parameters and Desupported Parameters sections, respectively.

      Adjust the values of the initialization parameters to at least the minimum values indicated by the Pre-Upgrade Information Tool.

      Make sure all path names in the parameter file are fully specified. You should not have relative path names in the parameter file.

   2. If the parameter file contains an IFILE entry, then change the IFILE entry in the parameter file to point to the new location of the include file that you specified in step 1. Then, edit the file specified in the IFILE entry in the same way that you edited the parameter file in Step a through Step d.

   3. If you are upgrading a cluster database, then you may need to modify the SPFILE or initORACLE_SID.ora files.

   Make sure you save all of the files you modified after making these adjustments.

3. If you are upgrading a cluster database, then set the CLUSTER_DATABASE initialization parameter to false. After the upgrade, you must set this initialization parameter back to true.