Amplifying ClickHouse Capacity with Multi-Volume Storage (Part 1)

Amplifying ClickHouse Capacity with Multi-Volume Storage (Part 1)

As longtime users know well, ClickHouse has traditionally had a basic storage model.  Each ClickHouse server is a single process that accesses data located on a single storage device. The design offers operational simplicity–a great virtue–but restricts users to a…

Silicon Valley ClickHouse Meetup Report

Silicon Valley ClickHouse Meetup Report

The latest San Francisco Bay Area ClickHouse Meetup was in Silicon Valley on August 13th. We had between 25 and 30 attendees at H2O.ai, who kindly hosted the event at their offices in Mountain View. The crowd was enthusiastic, leading…

New Encodings to Improve ClickHouse Efficiency

New Encodings to Improve ClickHouse Efficiency

July 10, 2019Modern analytical databases would not exist without efficient data compression. Storage gets cheaper and more performant, but data sizes typically grow even faster. Moore’s Law for big data outperforms its analogy in hardware. In our blog we already…

Managing ClickHouse Datasets with ad-cli

Managing ClickHouse Datasets with ad-cli

July 1, 2019Large datasets are critical for anyone trying out or testing ClickHouse. ClickHouse is so fast that you typically need at least 100M rows to discern differences when tuning queries. Also, killer features like materialized views are much more…

clickhouse-local: The power of ClickHouse SQL in a single command

clickhouse-local: The power of ClickHouse SQL in a single command

June 11, 2019The most interesting innovations in databases come from asking simple questions.  For example: what if you could run ClickHouse queries without a server or attached storage?  It would just be SQL queries and the rich ClickHouse function library….

Handling Variable Time Series Efficiently in ClickHouse

Handling Variable Time Series Efficiently in ClickHouse

May 23, 2019ClickHouse offers incredible flexibility to solve almost any business problem in a multiple of ways. Schema design plays a major role in this. For our recent benchmarking using the Time Series Benchmark Suite (TSBS) we replicated TimescaleDB schema…

Altinity ClickHouse Operator for Kubernetes

Altinity ClickHouse Operator for Kubernetes

Apr 9, 2019When I was setting up my first ClickHouse clusters 3 years ago it was like a journey to an unknown world full of caveats. ClickHouse is very simple and easy to use but not THAT simple. Sometimes I…

A Magical Mystery Tour of the LowCardinality Data Type

A Magical Mystery Tour of the LowCardinality Data Type

Mar 27, 2019Many ClickHouse features like LowCardinality data type seem mysterious to new users.  ClickHouse often deviates from standard SQL and many data types and operations do not even exist in other data warehouses. The key to understanding is that…

Updates and Deletes in ClickHouse

Updates and Deletes in ClickHouse

Oct 16, 2018It’s been two years already ago when ClickHouse development team published an excellent blog post “How to update data in ClickHouse”. In that old times ClickHouse supported only monthly partitions, and for mutable data structures, they suggested to…

Using ODBC with Clickhouse

Using ODBC with Clickhouse

20 Sept 2018This article shows different ways of how you can use ClickHouse in connection with other data sources to make queries use all of ClickHouse optimization features in order to make results come faster. Also, it is good practice…

Clickhouse-copier in practice

Clickhouse-copier in practice

Clickhouse-copier is a tool designed to copy data from one ClickHouse environment to another. The tool is a part of standard ClickHouse server distribution. It can work in a fully parallel mode and distribute the data in the most efficient…

Tableau with ClickHouse

Tableau with ClickHouse

ClickHouse users often require data to be accessed in a user-friendly way. There is a number of tools that can display big data using visualization effects, charts, filters, etc. Tableau is one of the popular ones. In this article, we…