How You Practice the Upgrade

You should run a trial upgrade as early as possible in the conversion cycle. Ideally, you should run trial upgrades more than once, so an isolated environment is desirable.

Follow this process:

Run a trial upgrade.
Take notes on what went wrong or what should be done differently.
Continue running trial upgrades until no more problems are encountered.
Note: Perform at least one of the trial upgrades on a full live data set so that you have an indication of how long the upgrade will take. This is particularly important when doing an unload/reload upgrade. In contrast, upgradedb type upgrades are largely insensitive to the amount of data in the database.
Give the annotated upgrade procedure to someone who can verify the upgrade plan.

How You Prepare a Build for the Live Upgrade

You should use a new build for the live upgrade.

As the date for the live upgrade approaches, follow this process:

Freeze all changes.
Delete all application objects and images from the development Ingres installation.
Re-image everything.
Use this refreshed copy for, at least, a critical functions test.
Use this build for the live upgrade.