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This is exactly what we need! Will try: https://github.com/ClickHouse/ClickHouse/issues/108247

It will be nicer if the README focuses more on per-core performance.

About the actual algorithm - will something like matching in a perfect hash table help?

Why not a wildcard DNS pointing to a few Anycast IP addresses with proxies?

https://github.com/ClickHouse/ClickBench/pull/983

Yes, it was a typo. Thank you!

https://pastila.nl/?cafebabe/5763fb6ec6db85bf0f20fbd710a8c83...

Just tested a few minutes ago on the ClickBench dataset. Overall quite good, but, depending on particular columns, most of the time slower - e.g., ~2.0 vs ~2.8 GB/sec on Graviton 4 machine in AWS.

You can look at the LZ4 decompression implementation in ClickHouse: https://presentations.clickhouse.com/2018-highload-siberia/ (the presentation is quite old, but the implementation was updated recently). It uses the same LZ4 format, just decompresses faster.

It is slower than LZ4 on AArch64.

Great article! About inserting LIMIT - we have out-of-band `limit` and `offset` settings:

https://play.clickhouse.com/docs?user=play#q=limit&name=limi...

ClickHouse also has vectorscan as a regexp engine, supporting multi- and fuzzy-matching, multi-Volnitsky for substring matching, as well as the new LLVM-JIT compiled regexp engine.

I've recently tested BQN on ClickBench (a benchmark for OLAP databases), and the results are not great: https://benchmark.clickhouse.com/#system=+N|liH&type=-&machi...

If anyone is curious how queries in this language look, you can see it here: https://github.com/ClickHouse/ClickBench/pull/939/changes#di...

Coding with AI is not much different from coding without AI, just faster and with slightly less typing. But you still have to organize the work and split it into small items. If you ask a model to implement a ray tracer in SQL, it can do something one-shot, but it won't be as satisfactory as with an engineer.

It is needed to find bottlenecks in the engine and optimize customer queries. For example, it gives things like: https://github.com/ClickHouse/ClickHouse/pull/108757

You can read more about this approach in my presentation: https://presentations.clickhouse.com/2026-openhouse-sf/great... and video: https://www.youtube.com/watch?v=FmS7VopaqNg

It is needed to find bottlenecks in the engine and optimize customer queries. For example, it gives things like: https://github.com/ClickHouse/ClickHouse/pull/108757

You can read more about this approach in my presentation: https://presentations.clickhouse.com/2026-openhouse-sf/great... and video: https://www.youtube.com/watch?v=FmS7VopaqNg

I host a publicly open database with Hacker News data at https://play.clickhouse.com/play?user=play#U0VMRUNUICogRlJPT...

So you can create any sort of similar services in a single SQL query and an HTML page.

I also hosted it as a publicly accessible data lake, which you can query from everywhere: https://github.com/ClickHouse/ClickHouse/issues/29693#issuec...

It is also updated in real-time.

Found one example that survived, and it was legitimate: https://github.com/ClickHouse/ClickHouse/pull/99522/changes

The CI only runs after one of the maintainers adds a "can be tested" label. When the label is already added, it stops when any of the infrastructure-related files are modified, like Dockerfile, CI configurations, etc. This is quite ok, but not 100% bulletproof, as you can easily do weird things by modifying the code or using a bug in the compiler. However, the CI infrastructure runs on isolated machines inside an isolated account.

Before adding the label, we have to check the diff for suspicious things. There were a few abuse attempts (all of them were from now vanished GitHub accounts).

There is already a database named EventQL: https://github.com/eventql/eventql I covered it in my presentation: https://presentations.clickhouse.com/2018-unknown_developers...

I've been trying for more than a year to make TursoDB load a single file, and it fails: https://github.com/ClickHouse/ClickBench/issues/336

The performance of hash tables and hash functions significantly depends on the data distribution, and should be compared on real datasets.

I've covered it in my presentation: https://presentations.clickhouse.com/2017-hash_tables/

Ground vehicles with transponders: https://adsb.exposed/?dataset=Planes&zoom=7&lat=42.1262&lng=...

https://github.com/ClickHouse/ClickHouse/pull/99828

Two problematic statements in this article:

1. Test pass rate is 99.98% is not good - the only acceptable rate is 100%.

2. Tests should not be quarantined or disabled. Every flaky test deserves attention.

Similarly, this is how it was introduced in ClickHouse in 2019: https://github.com/ClickHouse/ClickHouse/pull/4774

I once tried to post an interesting visualization to r/dataisbeautiful and received hundreds of upvotes, but then it was wiped for an unknown reason. Then I contacted the mods, both on Reddit and over email, to no avail.

It was a very frustrating experience, don't recommend anyone to try.

Though ClickHouse is not limited to a single machine or local data processing. It's a full-featured distributed database.

When a single server is not enough, you deploy ClickHouse on a cluster, up to thousands of machines, e.g., https://clickhouse.com/blog/how-clickhouse-powers-ahrefs-the...

This is bad news: it is not usable:

5.3 Licensee may not disclose any benchmarking or results of evaluating the Software without Exasol´s prior written consent

This is good news.

I was trying to add Exasol to ClickBench (https://github.com/ClickHouse/ClickBench/) since 2016, but it was not possible due to the limitations and the fact that it required using a custom virtual machine image.

Now we should try it again...

I would also like to have something like this, but for "vintage" links - something that looks like it was from the late 90s.

I use them in tests, just for fun: https://github.com/ClickHouse/ClickHouse/blob/master/tests/q...