MM-cat: A Tool for Modeling and Transformation of Multi-Model Data using Category Theory

Abstract

The support for multi-model data has become a standard for most of the existing DBMSs. However, the step from a conceptual (e.g., ER or UML) schema to a logical multi-model schema of a particular database, as well as its further correct maintenance, is not simple and straightforward.In this paper, we introduce MM-cat, a modular and extensible framework that enables to perform all the necessary steps to design a multi-model schema. An initial ER schema is transformed to a unified categorical representation which can then be easily mapped to any combination of models in a particular DBMS, or their set. In addition, MM-cat also provides a categorical representation of multi-model data instances to be processed uniformly. Both the schema and instance categories serve as the core for further management of multi-model data. The whole process of transformation to/from the categorical representation is demonstrated using MongoDB and PostgreSQL.