SQL for ClickHouse DBA

My name is Meo and I’ve been a DataBase Administrator (DBA) for the last 35 years of my life. After getting a degree at the University in Turin (Italy) many years ago, I started working with relational databases, and I’m still enjoying it! Sometimes I worked as a programmer, and later as an analyst, but my favourite job is the DBA. I’ve worked with Oracle, PostgreSQL, MySQL, and now with ClickHouse in XeniaLab.

The DBA uses particular SQL statements to extract the most interesting information from the databases it manages. This article describes some useful SQL commands a DBA must know to manage a ClickHouse database, like checking sessions, locks, disk space usage, performance and replication. This is my personal “Run Book,” and I am happy to share it in the Altinity blog.

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Introducing ClickHouse IPv4 and IPv6 Domains for IP Address Handling

May 21, 2019

One of our customers recently had a problem using CickHouse: the simple workflow of load-analyze-present wasn't as efficient as they were expecting. The body of the problem was with loading and presenting IPv4 and IPv6 addresses, which are traditionally stored in ClickHouse as UInt32 and FixedString(16) columns. These types have many advantages, like compact footprint and ease of comparing values. But they also have shortcomings that prompted us to seek a better solution.

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