Please play the Star Trek – Enterprise theme while you are reading this post. 🙂
I’ve mentioned database upgrades a few times over the last year or more. Like many others, we are pushing hard to get everything upgraded to 19c. Over the last couple of weeks a bunch more systems got upgraded, and we are now looking like this.
The remaining 11.2 and 12.1 databases are all in various stages of migration/upgrade. I would not curse us by giving a deadline for the final databases, but hopefully soon!
The reason for mentioning that theme song is it starts with the words, “It’s been a long road getting from there to here”, and that is exactly how it feels.
Many of the database upgrades are technically simple, but the projects surrounding them are soul destroying. Getting all the relevant people to agree and provide the necessary resources can be really painful. This is especially true for “mature” projects, where the, “if it ain’t broke, don’t fix it”, mentality is strong. I wrote about the problems with that mentality here.
I’m not going to give you any blinding insights into how to do your database upgrades, because every upgrade is potentially unique, as I discussed here.
We always go for the multitenant architecture (CDB/PDB) unless there is a compelling reason not to. I think we only have one non-CDB installation of 19c because of a vendor issue. None of our other 3rd party applications have had a problem with using PDBs, provided we’ve made sure they connect with the service, not a SID. We don’t use the USE_SID_AS_SERVICE_listener_name parameter. I would rather find and fix the connection issues than rely on this sticking plaster fix.
In know I’ve said some of these things before, but they are worth repeating.
- Oracle 19c is the current long term release, so it’s going to have support for a longer time than an innovation release.
- Oracle 21c is an innovation release. Even when the on-prem version does drop, you probably shouldn’t use it for your main systems unless you are happy with the short support lifespan.
- I recently heard there won’t be an Oracle 22c, so the next release after Oracle 21c will be Oracle 23c, which is currently slated to be the next long term release.
In short, get all your databases to Oracle 19c, and you should probably stick there until Oracle 23c is released, unless you have a compelling case for going to Oracle 21c.