ClickHouse vs PostgreSQL
The analytics database vs the everything database. One scans billions of rows in milliseconds. The other does everything else.
PostgreSQL
PostgreSQL is the right default database for almost everything. ClickHouse is the right analytics database. Unless your primary workload is analytical queries over billions of rows, start with Postgres. You can always add ClickHouse later for analytics.
OLAP vs OLTP
ClickHouse is an OLAP (Online Analytical Processing) database. It's designed for scanning massive amounts of data fast. Columnar storage, vectorized execution, insane compression. Aggregate queries over billions of rows return in milliseconds.
PostgreSQL is an OLTP (Online Transactional Processing) database. Individual reads, writes, updates, transactions. It can do analytics too, but it's not optimized for it.
When ClickHouse Shines
Event analytics, log analysis, time-series data, real-time dashboards over massive datasets. If you're querying "average response time per endpoint over the last 30 days across 500 million log entries" — ClickHouse does this in under a second.
PostgreSQL would choke on that query without significant optimization.
When PostgreSQL Is Better
Everything transactional. User accounts, orders, content management, CRUD operations. PostgreSQL has transactions, constraints, triggers, extensions (PostGIS, pg_vector, etc.), and the most complete SQL implementation.
ClickHouse doesn't do UPDATE well. Doesn't support transactions. Doesn't do JOINs efficiently. It's not a general-purpose database.
Quick Comparison
| Factor | ClickHouse | PostgreSQL |
|---|---|---|
| Analytical Queries | Blazing fast | Slow on large datasets |
| CRUD Operations | Not designed for this | Excellent |
| Transactions | Limited | Full ACID |
| Compression | 10-40x | Standard |
| JOINs | Limited/slow | Full support |
| Extensions | Few | Massive ecosystem |
| Data Ingestion | Millions of rows/sec | Thousands of rows/sec |
The Verdict
Use ClickHouse if: Your primary workload is analytics over large datasets. Event tracking, log analysis, metrics dashboards.
Use PostgreSQL if: You're building an application. Any application. PostgreSQL is the default for a reason.
Consider: Use both. PostgreSQL for your application data, ClickHouse for analytics. Pipe events from Postgres to ClickHouse.
PostgreSQL is the right default database for almost everything. ClickHouse is the right analytics database. Unless your primary workload is analytical queries over billions of rows, start with Postgres. You can always add ClickHouse later for analytics.
Related Comparisons
Disagree? nice@nicepick.dev