The upgradedb utility allows for a fast, in-place upgrade path for an older version Ingres database, with no additional disk space requirements. Because upgradedb is faster, it is typically the recommended way of upgrading.

Preparing for a safe and reliable upgradedb, however, can take time.

Databases using the system-maintained logical key feature are best upgraded using upgradedb. Tables that contain SYSTEM_MAINTAINED table_key or object_key columns cannot be safely unloaded and reloaded without additional work. The reload step generates all new logical key values. If there are other tables referencing the logical key columns, the new values must somehow be manually propagated to those other tables.