If you are upgrading from Ingres 6.4, you can use either the upgradedb or the unload/reload method.

Ingres 9.0 provides an improved upgradedb utility that allows 6.4 databases to be upgraded with minimal database preparation effort. You can follow the standard upgradedb procedure described in the chapter “Upgrading Using Upgradedb.”

Since most 6.4 databases are several years old, you may choose to use an unload/reload upgrade. Keep in mind that an unload/reload upgrade takes substantially more time and resources. If you choose the unload/reload method, follow the procedures in Unload/Reload Procedure for Upgrading from 6.4.

Regardless of the method chosen, however, an upgrade from Ingres 6.4 requires more planning and preparation than upgrades from newer versions, and you must follow the application and system preparation procedures described in Considerations for Ingres 6.4.

An alternative upgradedb procedure that requires extensive preparation, but will result in a successful upgrade under almost any circumstances, is described in Alternate Upgradedb Procedure.