Toward Co-existing Database Schemas based on Bidirectional Transformation

TL;DR

This paper proposes a new approach for managing co-existing database schemas using bidirectional transformation, enabling flexible and synchronized schema versions within a single database system.

Contribution

It introduces a systematic method for implementing co-existing schemas with bidirectional transformation, overcoming limitations of previous view-based approaches.

Findings

Co-existing schemas can be implemented using putback-based bidirectional transformation.

Extra functions are necessary to ensure totality in schema synchronization.

The approach supports flexible, synchronized multiple schema versions within one database.

Abstract

According to strong demands for rapid and reliable software delivery, co-existing database schema versions with multiple application versions are reality to contribute them. Current database management systems do not support co-existing schema versions in one database. Although a design of co-existing schema based on updatable view tables was previously proposed, its flexibility is limited due to pre-defined several restrictions to achieve data synchronization among schemas and handling independent unsynchronized data in each schema. In this preliminary report, we present a new approach for co-existing schemas based on bidirectional transformation. We explain the required properties to realize co-existing schemas, bidirectionality and totality. We show that the co-existing schemas can be implemented systematically by applying putback-based bidirectional transformation to satisfy both the bidirectionality and the totality. While the bidirectionality can be satisfied by applying bidirectional transformation, to satisfy the totality, extra functions need to be introduced. How to derive these extra functions is presented.