ClickHouse Black Magic, Part 2: Bloom Filters

ClickHouse Black Magic, Part 2: Bloom Filters

Bloom filters are an important ClickHouse index type with mysterious parameters. Take a closer look at the theory behind bloom filters, parameter selection using queries on a test dataset, and effective tuning.

Announcing the New Altinity & PostHog Partnership

Announcing the New Altinity & PostHog Partnership

Today we’re excited to officially announce our partnership with PostHog. We’ve worked with PostHog’s teams on this integration and have collaborated on ClickHouse-related topics since 2020. It’s great to be able to share with the wider open source analytics community what we’ve been working on together. 

Fixing the Dreaded ClickHouse Crash Loop on Kubernetes

Fixing the Dreaded ClickHouse Crash Loop on Kubernetes

As countless ClickHouse users have learned, Kubernetes is a great platform for data. It’s portable to almost every IT environment. But there’s still the occasional dark cloud. One of these is pod crash loops, which arise when a ClickHouse pod crashes on startup. This article shows how to diagnose and fix them.

Loading 100B Rows in Minutes in Altinity.Cloud

Loading 100B Rows in Minutes in Altinity.Cloud

A few weeks ago the SingleStore team published interesting research in their blog. They demonstrated how to load 100 billion rows in a database in 10 minutes. While it did not seem outstanding for ClickHouse, we were intrigued to learn how much faster we can accomplish the same task, so we conducted some experiments in Altinity.Cloud.

ClickHouse Black Magic: Skipping Indices

ClickHouse Black Magic: Skipping Indices

ClickHouse indices are different from traditional relational database management systems. Instead, ClickHouse uses secondary ‘skipping’ indices. Those are often confusing and hard to tune even for experienced ClickHouse users.

In this article we will dive into skipping indices and learn some of ClickHouse black magic.

A Day in the Life of a ClickHouse Query

A Day in the Life of a ClickHouse Query

This webinar is a gentle introduction to ClickHouse internals, focusing on topics that will help your applications run faster and more efficiently.