Database Upgrade High Level Steps From 11g to 12c

Database Upgrade High Level Steps From 11g to 12c.

Manual upgrade process are divided in 3 steps.

Step.1 pre-upgrade
Step.2 actual database upgrade
Step.3 post-upgrade

To perform pre-upgrade steps that you do not require downtime, you must be finished before downtime starts. Before starting upgrade process finish 12c installation on preffered mount point.

Source version: 11.2.0.3
Target version:12.1.0.2

1) Before starting the upgrade make sure Oracle 12c database binary already installed on the database server.
-Choose software only while installing 12chome

2) Check the integrity of the database by running (dbupgdiag.sql script)
-download the Oracle Database Upgrade Diagnostic Utility from support.oracle.com
-Check the invalid objects.
- Run utlrp.sql to validate invalid objects before upgrading process
-Check the duplicate objects owned by sys and system.
-purge recyclebin
-verify installed components status and version.
-check any corruption in data dictionary.

3) Run preupgrade information tool.
-Copy the Pre-Upgrade Information Tool script preupgrd.sql along with utluppkg.sql from the Oracle Database 12chome.
-Run preupgrd.sql
-It will generate below files
*preupgrade.log
*preupgrade_fixups.sql
*postupgrade_fixups.sql

4)  Review preupgrade.log script output.

5) Fix the warnings reported by preupgrade.log file.

6) Execute the preupgrade_fixup.sql
-preupgrade_fixups.sql script will attempt to resolve issues reported by the preupgrade process.
-Issues that cannot be resolved automatically by a fixup script are flagged with ** USER ACTION REQUIRED **.
-Disable cronjob
-check any files in media recovery/backup mode
-Check the timezone version
-Gather dictionary statistics
-Purge the Database RecycleBin Before Upgrading
-Remove EM repository

7) Stopping the 11g database components.

8) Backup the 11g home (preffered cold backup)

9)Set the 12c ENV variables and startup the database with upgrade.
-start with startup upgrade option.
-Run catupgrade script from os level with paralle=6 as below
cd $ORACLE_HOME/rdbms/admin
$ORACLE_HOME/perl/bin/perl catctl.pl -n  6 -l $ORACLE_HOME/diagnostics catupgrd.sql

10)  Run the Post-Upgrade Status Tool
-Execute post upgrade script- utlu121s.sql which provides a summary of the upgrade
-Execute catuppst.sql script
-Download the dst upgrade script from oracle
-Once dst upgrade is successful , validate the time_zone(It should be 18)
-Run postupgrade_fixup.sql, The postupgrade_fixups.sql script is created to address issues that can be fixed after the database has been upgraded.
-Change the ORACLE_HOME to 12c in listener.ora file.
-Run utlrp.sql
-Update the compatible parameter and restart database.