TimescaleDB is an open-source relational database designed for time-series data. It leverages PostgreSQL and offers features such as time-series specific functions, automated data retention, continuous aggregates, and native compression. The database can be deployed in various environments, including Timescale Cloud, and supports clustering via Postgres replication for high availability and scaling queries. TimescaleDB can replace process historians like OSIsoft Pi by creating custom relational tables with data modeling and tags. However, certain features like gapfill are only available in the Community edition. Native compression in version 1.5 is expected to provide significant improvements over ZFS block compression, offering better compression rates of 10-30x. The database handles alarms and events outside the database, often using third-party tools for alerting, such as Grafana.