In the process of planning an upgrade, consider the consequences of backing out of that upgrade. Consider the following information during your planning process:
| Type of Upgrade | Considerations for Backing Out |
|---|---|
| Patch/Maintenance Upgrade | Backing out of this upgrade requires a version switch and a database restart. MP-RAS systems may need a node reboot. |
| Minor Upgrade | Backing down from a minor version, such as 15.10 to 15.00 can only be done if the dbscontrol flag NoDot0Backdown has not been set to True. Once that flag is set to enable certain 15.10 features, the system cannot back down. If this flag is set, the only available backdown mechanism is to follow the process for backdown from a major upgrade. The applicable Upgrade Guide contains more information about backing down. |
| Installation/Migration Upgrade | You can only back out of this type of upgrade if your source system is still available. |
| Major Upgrade | This type of upgrade back out requires a version switch, sysinit, and data reload. You need to archive your data at the current release version to go back to it. For example, you cannot upgrade to Teradata Database Release 16.00 and go back to Release 15.00 using the same data. |