New Year Greetings and ClickHouse Updates

The year 2020 has been a tough one for the world. It changed the way people work, communicate and travel. It taught us to care more about family, friends, and colleagues. It highlighted the fragility of our world. Altinity and ClickHouse changed as well, but fortunately most changes were good.

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High Performance, High Reliability Data Loading on ClickHouse

Arrays are a prominent ClickHouse SQL extension that can accelerate query speed up to 100x in well-chosen use cases. This webinar introduces ClickHouse arrays and shows how to use them effectively. We provide examples of idiomatic usage and guides you on use cases where you should immediately reach for arrays. Please join us to become a power user of this popular ClickHouse feature.

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ClickHouse and S3 Compatible Object Storage

ClickHouse is a polyglot database that can talk to many external systems using dedicated engines or table functions. In modern cloud systems, the most important external system is object storage. It can hold raw data to import from or export to other systems (aka a data lake) and offer cheap and highly durable storage for table data. ClickHouse now supports both of these uses for S3 compatible object storage.

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Altinity Stable Release™ Update 20.3.19.4

We are delighted to announce that the ClickHouse Altinity Stable Release is updated to 20.3.19.4. This release includes several dozen bug fixes not present in the previous 20.3.12.112.

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ClickHouse vs Redshift Performance for FinTech Risk Management

ClickHouse SQL extensions, arrays, in particular, allow it to solve the business use case up to 100 times more efficiently than Redshift at 1/6th the cost. We know that ClickHouse is fast, but we were a bit surprised by these research results.

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ClickHouse and Redshift Face Off Again in NYC Taxi Rides Benchmark

Being that it has been roughly three years since we last compared ClickHouse to Amazon Redshift, we thought it was time for an update. Using the same popular benchmarking dataset of NYC taxi trips data over multiple years, current size is 1.3 billion rows.

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ClickHouse Birthday Altinity Stable Release 20.3.12.112

HAPPY BIRTHDAY, ClickHouse! In honor of ClickHouse turning 4, we have prepared several presents for ClickHouse users and ClickHouse itself: new releases of ClickHouse operator for Kubernetes, the Grafana ClickHouse Datasource and last but not least, the new Altinity Stable ClickHouse release.

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ClickHouse Dictionaries, Reloaded!

ClickHouse external dictionaries are a “ClickHouse way” to handle multi-dimensional schema. ClickHouse Dictionaries Explained was the very first article in the Altinity blog three years ago. ClickHouse has improved significantly since then, and dictionaries have achieved a new level of utility. In this article, I will explain two new cool ClickHouse features that completely change the way how dictionaries can be used. Change in a good sense, of course.

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Altinity Stable Release is updated to 19.16.19.85

We are delighted to announce that Altinity Stable Release is updated to 19.16.17.85. The release includes several bug fixes not present in the previous 19.16.14.65 release.

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Handling Real-Time Updates in ClickHouse

Mutable data is generally unwelcome in OLAP databases. ClickHouse is no exception to the rule. Like some other OLAP products, ClickHouse did not even support updates originally. Later on, updates were added, but like many other things they were added in a “ClickHouse way.”

Even now, ClickHouse updates are asynchronous, which makes them difficult to use in interactive applications. Still, in many use cases users need to apply modifications to existing data and expect to see the effect immediately. Can ClickHouse do that? Sure it can.

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Five Ways to Handle as-of Queries in ClickHouse

A common use case in time series applications is to get the measurement value at a given point of time. For example, if there is a stream of measurements, one often needs to query the measurement as of current time or as of the same day yesterday and so on. Financial market data analysis and all sorts of monitoring applications are typical examples.

Databases have different ways to achieve this task and ClickHouse is not an exception here. In fact, ClickHouse offers at least 5 different approaches. In this article, we will review and compare them.

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Altinity Stable Release update 19.16.14.65

We are delighted to announce that Altinity Stable Release is updated to 19.16.14.65. The release includes several important bug fixes not present in the previous 19.16.12.49, and one compatibility fix that is important for future upgrades.

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