As database technologies evolve, the distinctions between SQL and NoSQL become less clear. NoSQL databases like MongoDB may recommend some referencing and joins rather than embedding all entities into one document. At the same time, SQL databases allow denormalization and can store and index JSON documents. Some even provide MongoDB-compatible APIs for querying relational data, as seen in Oracle Database and PostgreSQL when used with FerretDB.

This session explores the core principles of data modeling. Should you embed multiple entities within a document or define references and foreign keys? What factors influence this decision: performance, flexibility, or query access patterns? We will examine the trade-offs between normalization and denormalization using examples relevant to SQL tables or NoSQL collections. Whether you are working with documents or rows, this talk will give you a deeper understanding of the appropriate modeling approach to persist your application objects.