ClickHouse Release Notes

ClickHouse is an exellent DBMS with very smart people working on it. Unfortunately, it still lacks some important communication procedures, and arguable the most wanted one is release notes. 

Altinity mission is to make ClickHouse use easy for everbody, and we will try to fill the gap between Yandex and end users. 

Below are release notes that Yandex team presented at the recent meetup in Ekaterinburg. It includes changes and new features appeared in latest 1.1.54231 release as well as some others that were not yet documented or publically explained.

ClickHouse Dictionaries Benchmarking

There are few ClickHouse benchmarks in the web already. Most of them use denormalized database schema. However, in denormalization is not always possible or desirable. In this article we will compare the query performance between denormalized and normalized schema where normalization is modelled using unique ClickHouse external dictionaries feature.

ClickHouse Dictionaries Explained

One of the most useful ClickHouse features is external dictionaries. They are extremely powerful, and if used efficiently may lead to quite elegant designs. I will lead you through the dictionaries using few examples that highlight basic and advanced usage scenarios. So let's begin.