Problemsby IbisTrouble with ClickHouse constant
Databases4 posts from 2 people3d active+00 posts in the last 7 days, 1 the 7 days before (fading)
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4, newest first`<=>`/`=` with nested NULL constant skips matching granules and parts### Describe what's wrong - `t (5, NULL)` and `a = [5, NULL]` can silently drop the matching row. - Happens when partition minmax, the primary key, or a `minmax` skip index covers the column. - Expected the matching row returned, actual query returns zero rows. - Row is lost...ClickHouse/ClickHouse · clickgapaiOpen ↗Stack-overflow SIGSEGV on SELECT of deeply nested constant `Dynamic` value### Describe what's wrong - A plain `SELECT` of a deeply nested constant `Dynamic` value crashes the server with a stack-overflow SIGSEGV at default settings. - Trigger: `finalizeAggregation` of a binary `AggregateFunction(any, Dynamic)` state with 4000 levels of...ClickHouse/ClickHouse · clickgapaiOpen ↗substring with a constant offset 0 throws on a non-constant string, other argument shapes return an empty string### Describe what's wrong `substring(s, 0, len)` throws `Indices in strings are 1-based` when `s` is a column and the offset is a constant. With a constant string, or with the offset as a column, the same call returns an empty string, which is what the documentation says. -...ClickHouse/ClickHouse · r33s3n61 repliesOpen ↗`GROUPING SETS` constant key dropped: empty-input `()` row lost or doubled### Describe what's wrong - With an aggregate and a grouping set made only of constant keys, empty input gives the wrong row count. - Trigger: `GROUP BY GROUPING SETS (('a'), ())` over `numbers(0)` with `count()`. - Expected one `()` row with count 0, but it returns no row at...ClickHouse/ClickHouse · clickgapaiOpen ↗
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About this problem
Evidence
4 posts from 2 people in 1 place, about 2 a week over 9 days. Mostly on ClickHouse/ClickHouse. Tools named alongside: GitHub.
Frustration Frustration 0 of 3· Seen on GitHub issues
How it was grouped
Posts about ClickHouse with no known issue, sharing the word "constant". First post Oct 4, 2026, latest Oct 12, 2026. Corroborated: 3 or more posts from 2 or more people or places. Method
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 readClickHouse error messages are crypticTrouble with ClickHouse slower
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Trouble with ClickHouse constant (3 posts)