40.2 Introduction

As described in Chapter 39, Freeze supplies a valuable set of services for simpli­fying the use of persistence in Ice applications. However, while Freeze makes it easy for an application to manage its persistent state, there are additional adminis­trative responsibilities that must also be addressed:

• Migration

As an application evolves, it is not unusual for the types describing its persis­tent state to evolve as well. When these changes occur, a great deal of time can be saved if existing databases can be migrated to the new format while preserving as much information as possible.

• Inspection

The ability to examine a database can be helpful during every stage of the application’s lifecycle, from development to deployment.

FreezeScript provides tools for performing both of these activities on Freeze map and evictor databases. These databases have a well-defined structure because the key and value of each record consist of the marshaled bytes of their respective Slice types. This design allows the FreezeScript tools to operate on any Freeze database using only the Slice definitions for the database types.