DortDB: Bridging Query Languages for Multi-Model Data Ponds

Multi-model data encompasses structurally distinct data, including relational, document, graph, key/value, columnar, etc., managed within a single system, such as a multi-model database or a data lake. Querying multi-model data requires strategies that balance unification and integration across diverse models and query languages. This paper presents DortDB, an extensible framework enabling cross-model queries combining well-known query languages and offering intuitive flexibility and optimization via a unified algebra. Though a small-scale in-memory prototype is to be demonstrated, its principles can be extended to distributed systems.