This paper presents flexible protocols for dynamic database design and reconfiguration, enabling mobile database to be designed in such a way that data location, replication and even use semantics can be changed dynamically. In particular, a dual data/currency hoarding and synchronization protocol, a metadata protocol and currency redistribution protocol are proposed. Metadata records the changing characteristics of replicas and currencies are dynamically redistributed to fit the target. Primaries may be diluted, concentrated and transferred in the system. Traditional distributed database is included as home of data. An ad-hoc database may check out its desired data/currency and check them back in when they are no longer accessed by the mobile users. We demonstrate that the flexibility of this approach can significantly improve commit performance under dynamic access and mobility behavior.