Over the years I have been involved in the migration and/or upgrade of many Oracle databases.
From these experiences I have built up a checklist of questions and considerations, which I feel should be properly addressed and answered before the migration or upgrade of any Oracle database. Some of these items are on the list from the bitter experience of having overlooked them.
I feel more of the items to be considered arise from the moving (i.e. re-hosting) of a database, rather than the upgrading of it. So, even if we were moving a database to exactly the same Oracle version on a new hardware platform, we would still have to address most of the items on this list.
I hope it’s useful to you and I will update it in future, every time I’m bitten by something new which I have overlooked.
Please point out in the comments anything you feel should be included.