FAQ: Why do Object IDs increment by 400 when editing ArcSDE geodatabases?
Why do Object IDs increment by 400 when editing ArcSDE geodatabases?
In a multi-user editing environment, Object IDs are assigned to clients in batches of 400. These Object ID batches are cached (all 400 values) and held until the edit session is closed. Then, the unused Object IDs are recycled so they can be used later. This is done by design to avoid unique ID conflicts. The ObjectID field can have a maximum value of 2,147,483,648.