Adam,
As a consultant, I would say there are a lot of "it depends" in how long it takes or should take. There is a lot happening with restructuring the application tier depending on whether you are running single node or multi-node with shared Appl_tops or non shared, have a DMZ configuration, etc. Re-layering any customizations or extensions or third-party add-ons can also create complexity (and time) for the upgrade. I would offer these suggestions:
1) looking at how to pre-stage the application tier file system with most of the content in place.
2) from your test cycles, build migrations of FNDLOAD setup info to minimize manual creation
3) There is a upgrade timing report that you can use to determine the long running parts of the process. Review it carefully for things like new index creation. We opted to pre-create some of the indexes in our production environment prior to the upgrade time where the columns already existed on the tables. Since we do significant partitioning, we were able to build those with our partition strategy and avoid rebuilding them after the upgrade.
4) Turn off database archiving during the upgrade as it adds significant overhead and your backup plan for the upgrade should address recovery without archive point-in-time recovery. That said - if it really is going to take several days, be sure to plan backups at key points in the process to ensure you can continue with the upgrade without losing significant time. I usually prefer backup points (snapshots if the storage system supports it) about every 12 hours.
Regards,
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Gary Chancellor
Vice President
IngenuitE, Inc.
Oklahoma City OK
(405) 636-1802
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Original Message:
Sent: 04-05-2021 16:49
From: Adam Cohen
Subject: Upgrading to 12.2.9 Experience
We are working on a project to upgrade from 12.1.3/12c to 12.2.9/19c. We have a handle on what's involved with upgrading the database technology, but in our trial runs upgrading applications to 12.2.9 is taking more than a week of DBA time during normal business hours. We are newly installing ECC and mobile as part of this project which adds some time.
What has been the experience of others upgrading from 12.1.3 to 12.2.9 (or similar versions)? How long was your upgrade window and how long long did it actually take? Are there any gotchas to look out for? Any tips?
We are using one of the larger consulting firms to help us out with this project including a DBA resource.