ClickHouse
What it is: Open-source columnar OLAP database. Real-time analytics on billions of rows. Developed by Yandex for web analytics at scale.
What It Does Best
Blazing fast queries. Scan billions of rows in seconds. 100-1000x faster than row-based databases for analytics.
Real-time ingestion. Query fresh data immediately. No ETL delays. Perfect for operational analytics.
Compression. 10x-100x compression ratios. Store more data, query it faster.
Pricing
Free: Open source, Apache 2.0. ClickHouse Cloud: $0.37/GB storage/month, $0.62/GB scanned. Free tier available.
When to Use It
✅ Real-time analytics dashboards
✅ Event and log analytics at scale
✅ Application monitoring and observability
✅ User behavior analytics
When NOT to Use It
❌ Transactional workloads (no full ACID)
❌ Frequent updates/deletes (optimized for inserts)
❌ Small datasets (overkill)
Bottom line: The fastest OLAP database you can run yourself. Cheaper than Snowflake, faster than most alternatives. Learning curve is real, but performance payoff is massive. Best for real-time analytics.