Why EAV Designs Fail in PostgreSQL
Entity-attribute-value (EAV) schemas—often described as "introspection on steroids"—may look promising in theory, but they crumble under real workloads. In practice, such designs only function acceptably with small datasets; once meaningful data volumes are introduced, both the database and the application can grind to a halt. A single production encounter with this pattern necessitated a full rewrite of both the application layer and the database schema to recover performance.
For teams tempted by schema-free flexibility, PostgreSQL's JSON and JSONB types offer a far more capable alternative. They support partial schema-less modeling without the EAV overhead, while simplifying multi-tenant or customer-specific deployments: since structural changes reside in the data rather than the schema, there is no need to orchestrate migration scripts for every client.
