Time-series databases optimize for timestamped data:
Use cases: Metrics, IoT sensors, financial data, logs. Write-heavy with time-based queries.
Optimizations: Columnar storage. Compression for sequential timestamps. Automatic data expiration (TTL).
Popular options:
- InfluxDB: Purpose-built, SQL-like query language
- TimescaleDB: PostgreSQL extension, full SQL
- Prometheus: Metrics and alerting, pull-based
Query patterns: Aggregations over time windows. Downsampling old data. Recent data at full resolution.