With a versioned table, you can create a snapshot of your data at a point in time, and, later, query the table as it existed then. You can undo changes back to any saved point. You can maintain multiple concurrent versions of your data, each evolving independently from a common ancestor. References Overview VTable is an access method that extends IDS with the ability to maintain versioned tables. When a user connects to the database, a default table state is assigned, and that user will see versioned tables as they appear for that state.
Users can also create new states that branch from existing ones.
In this manner, versioned tables can evolve along several parallel paths, with each path serving a different purpose. Note that if your database contains more than one versioned table, all of the versioned tables move in lock step with respect to states. When you create a new state, or set your session to work with a specific state, the state applies to all of the versioned tables defined for your database. This document will present an overview of VTable. Readers interested in understanding the utility in more detail should download the distribution and examine the registration scripts and the source code.