Summary
In this chapter, we discussed the possibilities of an upgrade scenario such as why an upgrade is necessary and also the prerequisites that are needed before commencing an upgrade process. We have demonstrated upgrade scenarios of Oracle Clusterware from Oracle 10g R2 to 11g R1 and then from 11g R1 to the latest Oracle 11g R2.
At the end of this chapter, we also briefly explained the process of how to downgrade an Oracle Clusterware after an 11g R2 upgrade to the previous version. You should now feel you have sufficient information and feel confident to plan your upgrade efficiently. Moreover, we strongly recommend that you take the current environment backups prior to performing any upgrade process. In the next chapter, we are going to discuss some of the best real-world scenarios, such as extending cluster capabilities by adding more nodes and converting a non-RAC database to RAC.