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r/Clickhouse

▲ 7 r/Clickhouse

Schema Management/ Migration

I was wondering what people use for Schema Management and Migration. I toyed with dbmate/ goose and they both have their quirks.

I saw this post from clickhouse that mentions Atlas but it seems CH is only supported for their pro plan.

golang-migrate is mentioned there though I was not very impressed with it for PSQL and they have open tickets for: TLS, among others. They also have tickets from 2021 that are about CH.

What do people use for a OSS solution? Atlas can be an option but it seems unnecessary for ensuring a SQL is applied and allowing rollback if needed.

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u/csgeek-coder — 5 days ago
▲ 4 r/Clickhouse

What is a good Clickhouse starting container image stack?

We want to roll out Clickhouse hosted locally in podman, for playing around with it and to evaluate if it fits our needs.

Is it enough to roll out the basic Clickhouse image, or would maybe a improved(?) image e.g. from altinity like here: https://hub.docker.com/r/altinity/clickhouse-server be better

I would more or less use the Docker installation guide https://docs.altinity.com/altinitystablebuilds/stablequickstartguide/docker-install/ and adapt it to use podman instead

Are there any other images or tools we should set up right from the start, e.g. for administration or data visualization etc.?

Or things we should be aware of when starting out?

Thanks for any info you can give us!

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u/mobilgroma — 8 days ago
▲ 14 r/Clickhouse

Has anyone tried the experimental ZXC codec?

I'm the author of ZXC, a lossless compression library built for fast decompression. Since CH 26.7 it ships as an experimental column codec, and I'd like to know if anyone here has tried it, even just on a test table.

https://clickhouse.com/docs/reference/statements/create/table/codec

Quick context: ZXC is asymmetric. Compression is slower, decompression is very fast, and the ratio sits between LZ4 and ZSTD. That suits data written once and scanned many times, which describes a lot of MergeTree workloads.

CH team ran an independent benchmark on ClickBench hits (Graviton4, ZXC 0.13.1, single-threaded). At the default level, ZXC decoded 1.8-2.6x faster than LZ4 on every column tested, with better ratios. https://pastila.nl/?cafebabe/16ae94cb2aba1cd26c656f3ded96d882.md

Fair warning: the format isn't stable until 1.0: (v1.0 is expected at the end of 2026)

I'd like to have feedbacks about:

  • Ratio and query speed vs LZ4 / ZSTD(1) on your data
  • Which column types it helps with, and which it doesn't
  • Any crashes, errors or odd behavior
  • CPU (x86 or ARM)

Thx

Repo: https://github.com/hellobertrand/zxc

u/pollop-12345 — 14 days ago