What is ClickHouse?

Clickhouse is an open-source columnar-oriented Database Management System (DBMS) used for online analytical processing (OLAP) created by Yandex. Currently, it powers the second largest web analytics platform, Yandex Metrica. It can also be considered the first open-source SQL data warehouse to ever match the scalability and performance of databases such as Veryica and Snowflake. Thanks to columnar storage and compression, ClickHouse achieved one of the best processing performances across its competitors. ClickHouse’s data processing speed reaches up to 30 GB/s and increases linearly when using distributed processing.

ClickHouse is the first open-source SQL data warehouse to match the performance and scalability of proprietary databases such as Sybase IQ, Vertica, and Snowflake. It includes the following features, such as:

  • Column storage that handles tables with trillions of rows and thousands of columns.
  • Fault-tolerance and read scaling thanks to built-in replication.
  • Outstanding aggregation through materialized views.
  • Features to solve real-world problems such as funnel analytics and last point queries.

ClickHouse development is driven by a community consisting of hundreds of contributors focused on solving real problems, not implementing corporate roadmaps.


ClickHouse’s technology was first developed over 10 years ago at Yandex, Russia’s largest technology company in 2009.

  • ClickHouse was developed by the Russian IT company Yandex for the Yandex. Metrica.
  • When raw data was stored in the aggregated form, then Metrica previously used a classical approach, and this approach helps to reduce the amount of stored data.
  • A different approach is to store aggregated data. Processing raw data requires a high-performance system since all calculations are made in real-time. A column-oriented DBMS is needed to handle analytical data on the entire internet scale to solve this problem.
  • The first ClickHouse prototype appeared in 2009.
  • End of 2014, Yandex. Metrica version 2.0 was released. The new version has an interface for creating custom reports and uses ClickHouse for storing and processing data.

Features of ClickHouse

Here are the following main features of the ClickHouse, such as:

  • True column-oriented DBMS: No extra data is stored with the values. It means that the constant length values must be supported to avoid storing their length “number” next to the values.
  • Linear scalability: It is possible to extend a cluster by adding servers.
  • Fault tolerance: The system is a cluster of shards, where each shard is a group of replicas. ClickHouse uses asynchronous multi-master replication and can be deployed across multiple data centers. Data is written to any available replica and distributed to all the remaining replicas. Zookeeper is used for coordinating processes but not involved in query processing and execution.
  • SQL support: ClickHouse supports an extended SQL language that includes arrays and nested data structures, approximate and URI functions, and the availability to connect an external key-value store.
  • High performance: Vector calculation approach is used for high CPU performance. In this approach, data is stored by columns and processed by vectors (parts of columns). It supports sampling and approximate calculations. And also, parallel and distributed query processing are available, including JOINs.
  • HDD optimization: The system can process data that doesn’t fit in random access memory.
  • Blazing fast: ClickHouse uses all available hardware to its full potential to fastest process each query.
  • Easy to use: ClickHouse is simple and instantly available for building reports. SQL language allows expressing the desired result without involving any custom non-standard API found in some alternative systems.
  • Highly reliable: ClickHouse DBMS can be configured as a distributed system located on independent nodes, without any single failure points. It also includes a lot of enterprise-grade security features and fail-safe mechanisms against human errors.
  • Clients for database connectivity: Database connection options include the console client, the HTTP API, or one of the wrappers. A JDBC driver is also available for ClickHouse.

What you can do with ClickHouse?

  • Query billions of table rows and gigabytes of data in seconds
  • Run your OLAP queries efficiently with speed and accuracy
  • Join data across various sources – including local clusters and external systems
  • Configure ClickHouse as a distributed system on independent nodes without worrying about any failure
  • Ingest all your structured data into the database and use it for real-time reporting

Why ClickHouse is the Best Choice for Improvado?

As a fully automated marketing ETL platform, Improvado offers managed warehouse services to our clients. Since we are marketers ourselves, we understand how much data means when it comes to building and adjusting campaigns. Artificial constraints like pricing per query combined with low performance poorly affect the outcomes of analysis and campaign optimization. That’s why we searched for a solution that processes data quickly and doesn’t put any limitations on the analysis process. ClickHouse appeared to be the best candidate.

Unlike other columnar databases, ClickHouse not only stores data but also processes it in columns. This leads to a far more balanced and efficient CPU cache utilization and allows for SIMD CPU instructions usage. Besides, ClickHouse is a very scalable solution. It can utilize all CPU cores to execute a single SQL query.

ClickHouse Pricing Model

So, what’s so special about ClickHouse apart from its performance? Its enormous execution speed can be achieved at almost no cost. ClickHouse doesn’t charge any money if you want to deploy it on your physical machines. But, if you considered Snowflake or Redshift, an on premise solution is most likely not the thing you’re looking for.

The key benefit of ClickHouse lies in its reasonable pricing terms. Unlike other data warehouses, ClickHouse allowed us to build a predictable pricing model that doesn’t charge money for each operation with data. Analysts can focus on pure analysis without thinking about rational usage of credits, tokens, or whatever currency your platform has with limitless access to data and queries.

Wrapping Up

As it comes clear, ClickHouse is a versatile tool that, combined with an automated data pipeline, grants unlimited possibilities for marketing analysts. An outstanding performance, cost-effectiveness, and interoperability with business intelligence tools make ClickHouse a strong alternative to popular solutions. Now, marketers don’t have to worry about spending too many resources on experiments and fully dedicate themselves to marketing analysis.

I hope you like this blog. Thank You!!

Rajesh Kumar
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