Database and data platform products store, query and analyse an organisation's structured data. The category spans relational and document databases, data warehouses, managed database services and analytics platforms. Organisations choose them to run applications, consolidate reporting data and analyse large volumes. Oracle, Snowflake and Amazon's managed database services are common reference points, while PostgreSQL and other open-source engines can run almost anywhere.
Because a database sits underneath applications, the sovereignty question is about control rather than features. With a managed service the provider operates the machines, backups and often the encryption keys, so its staff and its jurisdiction determine who can reach the data. Proprietary extensions, query dialects and storage formats make migration slow and risky, and the data transfer costs of leaving can be substantial. Open engines reduce this dependence, but only if you avoid vendor-specific features.
When choosing a European option, ask who holds the encryption keys and whether you can bring your own, where replicas and backups are located, and how support staff access production data. Check compatibility with standard SQL and common wire protocols, documented export of data and schema, and the ability to move between a managed service and self-hosting.