I’ve had some interesting discussions with Anil Nair, our RAC Product Manager and a customer in the past days. The customer was looking for a definite statement that they can have a higher version of Patch Set Updates (PSUs) or Proactive Bundle Patches (BPs) in the Database homes than in the Grid Infrastructure home managing the resources.
For Oracle Database 18c, 19c and onward, please read instead:
Can you have different PSU/BP versions between Database and GI homes?
Yes, you can have a higher version PSU or BP in the Database home than in the Grid Infrastructure home managing the resources. This is implicitly documented in MOS Note 337737.1 – Oracle Clusterware (CRS/GI) – ASM – Database Version Compatibility where it says:
“The Oracle Grid Infrastructure (GI) /Clusterware (CRS) version must be of the highest version down to the 4th digit in the possible combinations at all times.“
Therefore you can deviate that this rule does not apply for the 5th digit anymore. Anil and I discussed that this may be documented a bit more clear – and he will take care.
Should you have different PSU/BP versions between Database and GI homes?
Well, this question is a bit harder. I can see why some customers have a higher patch level (5th digit) in the Database homes than in their GI homes. Actually some of my customers have this setup as well. GI is pretty stable above a certain patch level and often gets not treated with the same importance than the database homes as the need for patching in database homes is more obvious and visible. When it’s stable don’t touch it. And honestly speaking, patching is no fun – but hard work.
But we strongly recommend that you keep your patch levels in synch. If you apply the GI PSU of April 2017 then please apply the Database PSU or BP of April 2017 as well. These are the combinations we test internally. Please bear in mind that while the GI and DB are separate entities, they are tightly integrated and work cohesively. This way you mitigate the potential risk of an untested issue by having differences in the 5th digit.
And as a final hint:
Grid Infrastructure PSUs (and BPs) can be applied always in a rolling fashion causing no downtime. Just saying …