Personal experience from AllegroStore, a predecessor of AllegroCache: - In AllegroCache/AllegroStore, the class definition is the schema definition; so if the

Personal experience from AllegroStore, a predecessor of AllegroCache: - In AllegroCache/AllegroStore, the class definition is the schema definition; so if the newcomer understands class structures he understands the schema. - Hot-patching can be done through plain-old REPL. At least AllegroStore the system took care of key consistency (if it is explicit to the system). - In AllegroStore schema change is handled as class change (of persistent instances). So you can use usual MOP to write update function, which corresponds to the change scripts. The main difficulty, compared to RDBMS, seemed to come from the fact that the stored objects directly formed a graph, not a table. Some people seemed to have a hard time to "think" directly in graphs, and preferred table analogy.