Plan Your Upgrades
The upgrade process entails additional planning steps compared to updates, to properly plan an upgrade ensure the following points are considered before starting an upgrade.
Before starting to plan for an upgrade the following things must be considered:
Planning your upgrade is broken down into four steps:
- Become familiar with the features of the new release of Oracle Database
- Determine the upgrade path to the new release
- Select an upgrade method
- Select an Oracle home directory for the new release
- Develop a testing plan
- Prepare a backup strategy
- Follow pre-upgrade recommendations
- Run a pre-upgrade fixup scripts, or perform manual pre-upgrade system updates
- Define your upgrade goals: There are many reasons for you to embark on an upgrade journey, for example: you might be running on an older database version and have no support from Oracle to fix the issues, or your compliance policy suggests that you should be on newer version. Whichever be the reason, you must ensure that to call your upgrade successful, in terms of upgrade process, performance acceptance, outage duration, business impact due to non-availability and schedule of upgrade are clearly stated and called out.
- Define your upgrade policies: Your upgrade policy must take care of your rollback scenarios. These could be related to failed upgrades, poor database performance after upgrade. You must also take into consideration that rollback will add to the non-availability of database.
Similar to rollback, you should also consider cleanup of unused Oracle Homes. Once upgrade is successfully complete and all participating teams have signed off the results post upgrade, based on your cleanup policy, you should remove the unused homes.
- Organize:
- Amount of images: It is recommended that you have the fewest number of images as possible, maintaining large numbers of images can add greatly to the maintenance overhead. Images can be based on you different application types, data center name or location, application usage (test, development, production, or master).
- Targets to subscribe per image: Based on the criteria for image creation, a similar criteria can be followed for image subscription for targets. You can have a gold image for a particular application type such as ERP and subscribe all the ERP supporting databases to this image.
- Consolidation plans: An upgrade is an opportunity to re-organize your database estate. Aim to consolidate wherever possible and reduce the number of databases, Multi-tenant is the way forward. Try to consolidate multiple unique databases into one or more Container databases (CDB).
- Prepare for SQL Performance Analytics: Its important to have a benchmark for SQL performance so that you can review, analyze and fix any SQL queries that are performing poorly after database upgrade.