InfluxDB

Purpose-built for metrics and monitoring. Native time-series compression and downsampling (continuous queries). Flux query language. Best for: IoT telemetry, infrastructure metrics. Weakness: no JOINs, poor at general-purpose analytics.

TimescaleDB

PostgreSQL extension adding hypertables, continuous aggregates, and time-series compression. Full SQL with JOINs. Best for: teams already on Postgres who need time-series performance. Compression achieves 90–95% size reduction vs standard Postgres tables.

ClickHouse

Columnar OLAP database designed for analytics at scale. Ingests billions of rows/day, sub-second query response on terabyte datasets. Not PostgreSQL-compatible but uses SQL. Best for: high-cardinality time-series analytics, log analytics, user behaviour analytics.

Recommendation

  • Already on Postgres + moderate scale → TimescaleDB.
  • Pure metrics/monitoring → InfluxDB or Prometheus + Thanos.
  • High-volume analytics → ClickHouse.