Problemsby IbisClickHouse error messages are cryptic
Dev tooling4 posts from 2 people3d active+00 posts in the last 7 days, 0 the 7 days before (fading)
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The posts behind it
4, newest first`FETCH PARTITION` of a patch partition applies another table's updates### Describe what's wrong - `FETCH PARTITION ID 'patch-...'` from another table plus `ATTACH PARTITION ID` is accepted and the fetched patch rewrites rows of the destination.** - `t_dst` row `id = 1` holds `v = 100`; after fetching and attaching `t_src`'s patch for `UPDATE t_src...ClickHouse/ClickHouse · clickgapaiOpen ↗Parallel replicas return a wrong count() for a primary-key range predicate: the exact-count optimization's granules are dropped from the result**Company or project name:** - **Describe what's wrong** `SELECT count() FROM t WHERE ` with task-based parallel replicas returns only the rows of the granules the predicate matches partially, silently dropping the count of every granule it matches fully, when no local-replica...ClickHouse/ClickHouse · zlareb1Open ↗Plain MergeTree silently and permanently loses a column's data when a partition is detached before RENAME COLUMN and re-attached after it### Describe what's wrong On a plain `MergeTree` table, a partition detached before an `ALTER TABLE ... RENAME COLUMN` and re-attached after it silently loses the renamed column's data: `ATTACH PARTITION` succeeds with no error and the renamed column reads its default for every...ClickHouse/ClickHouse · zlareb1Open ↗Text index on `FixedString` with `String`-returning preprocessor drops all rows### Describe what's wrong - Queries with `equals`, `IN`, `has`, `hasAny` and `mapContainsKey` prune every granule and return nothing. - Triggered by a text index on a `FixedString(N)` column with a preprocessor like `CAST(s, 'String')` and a term-preserving tokenizer. - Expected...ClickHouse/ClickHouse · clickgapaiOpen ↗
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About this problem
Evidence
4 posts from 2 people in 1 place, about 2 a week over 14 days. Mostly on ClickHouse/ClickHouse. Tools named alongside: GitHub, Text.
Frustration Frustration 0 of 3· Seen on GitHub issues
How it was grouped
Posts that state a pain and match the "errors-unclear" rule about ClickHouse. First post Sep 23, 2026, latest Oct 6, 2026. Corroborated: 3 or more posts from 2 or more people or places. Method
The same problem elsewhere
Error messages are cryptic and unhelpfulOllama error messages are crypticDuckDB error messages are crypticPostgreSQL error messages are crypticClaude Code error messages are crypticLangChain error messages are crypticClaude error messages are crypticdbt error messages are crypticPyTorch error messages are crypticBigQuery error messages are crypticpandas error messages are crypticGitHub error messages are cryptic
Other ClickHouse problems
ClickHouse upgrades break working setupsTrouble with ClickHouse jsonClickHouse costs outgrow the value it givesClickHouse users keep filing bugsTrouble with ClickHouse columnTrouble with ClickHouse rowsExperiments on ClickHouse are hard to reproduce and trackTrouble with ClickHouse joinTrouble with ClickHouse nameTrouble with ClickHouse readTrouble with ClickHouse constantTrouble with ClickHouse slower
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ClickHouse error messages are cryptic (4 posts)