Clickhouse
ClickHouse® is a real-time analytics database management system
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What is Clickhouse?
ClickHouse is a fast open-source column-oriented database management system (DBMS) designed for online analytical processing (OLAP). It allows users to generate analytical data reports in real-time using SQL queries, delivering millisecond query results even at petabyte scale. ClickHouse is the leading database for AI, powering agentic systems with blazing-fast vector search, instant aggregations, and scalable training for machine learning and GenAI applications.
Key features include real-time analytics with ability to ingest millions of rows per second and analyze billions of rows with millisecond results, built-in observability for storing logs/metrics/traces using ClickStack, data warehousing capabilities with best-in-class compression ratios, and 100+ integrations for data ingestion and visualization. ClickHouse supports vector search for AI applications, materialized views for pre-aggregating metrics, and works with familiar SQL syntax including joins, window functions, arrays, and JSON.
ClickHouse is ideal for data engineers, data analysts, developers building real-time data products, and organizations handling modern data challenges like real-time dashboards, user behavior analytics, fraud detection, e-commerce optimization, gaming analytics, and ML/GenAI workloads. Companies like Anthropic, Tesla, Lyft, Sony, Cisco, and GitLab trust ClickHouse Cloud for its scale, efficiency, and ease of use.
Clickhouse pricing
Pricing model: Freemium
ClickHouse offers multiple pricing options: (1) Free open-source ClickHouse that you can download and self-host, (2) ClickHouse Local for querying local files without a server, (3) ClickHouse Cloud with three tiers: Basic tier includes up to 1 TB storage, 8-12 GiB memory, 24h backups retained for 1 day, 1 availability zone, Google/Microsoft SSO, and MFA for testing new ideas; Scale tier includes unlimited storage, configurable memory, compute-compute separation, 2+ availability zones, 1-hour 24x7 Severity 1 support, private networking, and automatic vertical scaling for production; Enterprise tier adds SAML SSO, private regions, custom hardware profiles (HighMemory/HighCPU), export backups to own cloud, Enterprise support with 30-min response, Lead Support Engineer, CMEK encryption, scheduled upgrades, consultative migrations, and HIPAA/Payments compliance. ClickPipes rates are $0.04/GB for ingested data and $0.20/hr per compute unit. Pricing is metered by compute, storage, data transfer, and ClickPipes usage with autoscaling that scales unused resources to zero.
Clickhouse pros
- Blazing fast query performance with millisecond results at petabyte scale
- Column-oriented storage enables 100x faster OLAP query processing
- Best-in-class compression ratios reduce storage costs significantly
- Real-time data ingestion of millions of rows per second
- Simple SQL syntax familiar to developers with SQL experience
- Open-source with MIT license and active community (47.6k+ GitHub stars)
- Vector search support for AI and GenAI applications
- 100+ integrations with data ingestion and visualization tools
- Scales both vertically and horizontally effortlessly
- Materialized views for pre-aggregating metrics at insert time
- Native support for JSON, arrays, and window functions
- Cost-effective with metered pricing and autoscaling to zero
- Security and compliance including HIPAA and PCI compliance on Enterprise
- ClickHouse Cloud available on AWS, GCP, Azure marketplaces
- ClickHouse Local allows querying local files without a server
- High query concurrency for interactive applications at scale
- Dedicated observability stack (ClickStack) for logs, metrics, traces
Clickhouse cons
- Not designed for OLTP transactional workloads
- No full ACID transaction support
- UPDATE/DELETE operations are limited and not fast
- JOINs are expensive, better suited for denormalized schemas
- Steep learning curve for cluster management and optimization
- Querying at cluster level is not trivial
- Kafka Engine can have stability issues with duplicates
- SSO compatibility missing some identity providers like Okta
- SQL Console Web UI lacks visual query plan features
- Role management in Cloud limited to admin/developer tiers
Frequently asked questions about Clickhouse
What is ClickHouse?
ClickHouse is a high-performance, column-oriented SQL database management system (DBMS) for online analytical processing (OLAP). It is available as both open-source software and a cloud offering. ClickHouse is the fastest and most resource efficient real-time data warehouse and open-source database, designed to generate analytical reports using SQL queries in real-time.
Why is ClickHouse so fast?
ClickHouse is fast because column-oriented databases are at least 100x faster in processing most OLAP queries compared to row-oriented databases. ClickHouse uses all available system resources to their full potential to process each analytical query as fast as possible, with vectorized execution, parallelized query pipeline, and best-in-class compression that maximizes CPU efficiency.
What is ClickHouse Cloud?
ClickHouse Cloud is the best way to use ClickHouse, available on AWS, GCP, Azure and their respective marketplaces. It offers three tiers (Basic, Scale, Enterprise) with automatic scaling, managed infrastructure, and features like private networking, configurable backups, and enterprise compliance. It scales storage and compute separately and automatically scales unused resources down to zero.
Can I use ClickHouse for OLTP workloads?
No, ClickHouse is not designed for OLTP (online transaction processing). It was built as an OLAP database for analytical queries and cannot handle high RPM load scenarios and transactions. ClickHouse expects data to remain immutable and does not support full ACID transactions. For transactional workloads, use MySQL, PostgreSQL, or MS SQL instead.
What use cases is ClickHouse built for?
ClickHouse is built for real-time analytics (user-facing dashboards, e-commerce optimization, fraud detection), observability (logs, metrics, traces with ClickStack), data warehousing (instant data exploration and insights), and ML & GenAI (vector search, instant aggregations, scalable training). It powers applications requiring millisecond queries at petabyte scale.
Is ClickHouse open source?
Yes, ClickHouse is open-source software with an MIT license. It has 47.6k+ GitHub stars, 2.9k+ contributors, 28.9k+ PRs, and 796+ releases. You can download and install ClickHouse for MacOS, Linux, FreeBSD, Windows, or Docker, or try it without installing in their playground.
What integrations does ClickHouse support?
ClickHouse has 100+ integrations in its growing ecosystem for data ingestion, visualization, and language clients. Popular integrations include Grafana, Tableau, Superset, Metabase, DBT, Langfuse, and Vector. It supports seamless integration with your data stack for streaming sources and favorite visualization tools.
How does ClickHouse handle UPDATE and DELETE operations?
UPDATE/DELETE operations in ClickHouse are limited and not fast. ClickHouse expects data to remain immutable. Updates and deletes are typically handled using ReplacingMergeTree table engine or TTL (Time To Live) clauses. Removing big chunks of data is technically possible but not fast since ClickHouse isn't designed for frequent data modifications.
What is ClickHouse Local?
ClickHouse Local allows you to run fast queries on local files (CSV, TSV, Parquet, and many more) without needing a database server. It's useful for quick data exploration and querying files directly without setting up infrastructure.
What makes ClickHouse good for AI and GenAI?
ClickHouse powers AI and GenAI with blazing-fast vector search for similarity queries, instant aggregations for ML training data, and scalable infrastructure for training workloads. It is the leading database for AI, powering agentic systems with millisecond queries at petabyte scale. ClickHouse also acquired Langfuse, the leading open-source platform for LLM observability, evaluations, and prompt management.