Relational databases offer a flexible and scalable solution for handling complex IoT data. They provide a broad ecosystem of tools, such as SQL, which is compatible with many administration tools, streaming pipelines, messaging protocols, visualization tools, industrial automation platforms, and extensions for working with geospatial and other datatypes. This makes it easy to build applications on top of existing IoT infrastructure. Relational databases also support JOINs, aggregations, window functions, common table expressions, and rollups, which enable complex queries. They offer a flexible schema that can be adjusted and updated using DDL commands, allowing for improved performance and data modeling. Additionally, relational databases provide reliability through ACID properties, ensuring transactions are processed reliably. PostgreSQL + TimescaleDB is a recommended choice for IoT developers due to its popularity, stability, and feature set.