Josch: Managing Schemas for NoSQL Document Stores

NoSQL document stores have become vastly popular. One major selling point is their flexibility w.r.t. schema management: With MongoDB, developers can actually switch back-and-forth between operating in schema-free mode, and schema fixed mode, where all write operations are validated. In this tool demo, we present Josch, which integrates state-ofthe-art third-party tools to support novel workflows for NoSQL document stores: Using Josch, DevOps teams may (1) extract a JSON Schema declaration from the production data instance, (2) manually refactor the schema (e.g., to account for upcoming schema changes), and (3) compare the extracted and the refactored schema, on a semantic level, e.g., to ensure that the rewritten schema is a generalization. (4) Finally, they may register the refactored schema with the NoSQL document store for schema validation. Apart from supporting this and other practical use cases, one further contribution of our demo is that we reveal current blind spots in NoSQL schema management tools that inspire novel research questions.