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ClickHouse

80 indexed repositories · View on GitHub

ClickHouse
ClickHouse® is a real-time analytics database management system

C++ · 50640 stars
clickhouse-go
Golang driver for ClickHouse

Go · 3355 stars
clickhouse-java
ClickHouse Java Clients & JDBC Driver

Java · 1629 stars
ClickBench
ClickBench: a Benchmark For Analytical Databases

Shell · 1147 stars
mcp-clickhouse
Connect ClickHouse to your AI assistants.

Python · 898 stars
clickhouse-rs
Official pure Rust typed client for ClickHouse DB

Rust · 567 stars
agent-skills
The official Agent Skills for ClickHouse and ClickHouse Cloud

TypeScript · 561 stars
clickhouse-connect
Python driver/sqlalchemy/superset connectors

Python · 533 stars
adsb.exposed
Interactive visualization and analytics on ADS-B data with ClickHouse

JavaScript · 467 stars
ch-go
Low-level Go Client for ClickHouse

Go · 431 stars
clickhouse-cpp
C++ client library for ClickHouse

C · 386 stars
dbt-clickhouse
The Clickhouse plugin for dbt (data build tool)

Python · 365 stars
silk
Fast stackful fibers with a NUMA-aware work-stealing scheduler

C++ · 332 stars
clickhouse-js
Official JS client for ClickHouse DB

TypeScript · 330 stars
clickhouse-operator
Official Kubernetes Operator for ClickHouse®

Go · 310 stars
NoiSQL
NoiSQL — Generating Music With SQL Queries

SQL · 294 stars
pg_clickhouse
Interfaces to query ClickHouse databases from PostgreSQL

C · 294 stars
clickhouse-odbc
ODBC driver for ClickHouse

C · 285 stars
graphouse
Graphouse allows you to use ClickHouse as a Graphite storage.

Java · 260 stars
walshadow
Sub-second Postgres replication to ClickHouse using physical WAL

Rust · 249 stars
60 more repositories live on View on GitHub

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Evaluate libbz2-rs-sys as an opt-in bzip2 replacement: compatibility, benchmarks and slow-case optimization
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comp-rust

Difficulty 5/5 Over a week Newbie friendliness 15/100

ClickHouse/ClickHouse#128411 · 1 comment · Opened Oct 31, 2026

Maintainers usually reply within 1 day
Reading a view whose body has two `ARRAY JOIN`s fails with `NOT_IMPLEMENTED` since 26.8
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comp-view potential bug

Difficulty 2/5 1-3 hours Newbie friendliness 80/100

ClickHouse/ClickHouse#128410 · Opened Oct 31, 2026

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`SELECT *` over a wide subquery/view: column-origin lookup is O(columns²)
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ai_p3 comp-query-analyzer

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128409 · Opened Oct 31, 2026

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Allow specifying alternative compression codecs when one does not apply for all data types.
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comp-codecs feature

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128405 · Opened Oct 31, 2026

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Unquoted alias `fetch` now fails with SYNTAX_ERROR
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ai_p3 comp-sql-syntax

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

ClickHouse/ClickHouse#128399 · 2 comments · Opened Oct 31, 2026

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Flaky test: 05345_feature_tier_settings_profile_to_all
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comp-testing flaky test testing

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128376 · 2 comments · Opened Oct 31, 2026

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Iceberg tables are much slower than MergeTree in the performance tests: subcolumns, sort order, join planning, position deletes
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comp-datalake performance

Difficulty 4/5 3-5 days Newbie friendliness 25/100

ClickHouse/ClickHouse#128374 · Opened Oct 31, 2026

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`SET profile` / `SETTINGS profile` / `?profile=` bypass `CONST` constraints for users defined in users.xml, contrary to the constraints docs
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comp-settings

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128370 · Opened Oct 31, 2026

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Under concurrent load GROUP BY loses the adaptive aggregator: one-thread plans are rejected (Q32 at max_threads=1 −61%, ClickBench 10-client QPS ×1.35)
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comp-aggregation performance

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128368 · 1 comment · Opened Oct 31, 2026

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COUNT(DISTINCT) with GROUP BY over few groups: deduplicate the (key, value) pairs by radix partitioning, also next to other aggregates (ClickBench Q8 -38%, Q9 -24% over current master)
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comp-aggregation performance

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128364 · 3 comments · Opened Oct 31, 2026

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`NOT (coalesce(a, b) > c) OR ...` loses rows with combined skip indexes
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ai_p2 comp-skip-index

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128360 · Opened Oct 31, 2026

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test-runner: splitQueries() mis-splits $$ heredocs and escaped backticks (8 upstream tests affected)
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Difficulty 2/5 1-3 hours Newbie friendliness 84/100

ClickHouse/clickhouse-js#1096 · Opened Oct 31, 2026

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Docs: naiveBayesClassifier has conflicting duplicate configuration instructions
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comp-documentation

Difficulty 2/5 1-3 hours Newbie friendliness 85/100

ClickHouse/ClickHouse#128350 · Opened Oct 31, 2026

Maintainers usually reply within 1 day
Query condition cache: keep the rows a PREWHERE selects, so a repeated query does not evaluate the condition again (repeated ClickBench Q41 -36%, Q40 -36%, Q42 -30%, Q38 -24%, Q30 -22%)
Open
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comp-mergetree performance

Difficulty 4/5 3-5 days Newbie friendliness 30/100

ClickHouse/ClickHouse#128347 · 3 comments · Opened Oct 31, 2026

Maintainers usually reply within 1 day
Mutations hang after MATERIALIZE TTL with ttl_only_drop_parts on ReplicatedMergeTree
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comp-ttl external potential bug

Difficulty 4/5 3-5 days Newbie friendliness 35/100

ClickHouse/ClickHouse#128331 · Opened Oct 31, 2026

Maintainers usually reply within 1 day
Memory table read estimate ignores WHERE/PREWHERE, causing bad join swap
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ai_p3 comp-query-optimizer

Difficulty 3/5 1-2 days Newbie friendliness 70/100

ClickHouse/ClickHouse#128297 · Opened Oct 30, 2026

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ALTER UPDATE of a parent column leaves Wide-part subcolumn skip index stale
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ai_p2 comp-mutations

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128280 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Synthetic `READ_COLUMN` trips `throw` mode: Wide `MATERIALIZE INDEX` stuck
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ai_p2 comp-mutations

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128279 · Opened Oct 30, 2026

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Compact symbols decompress a granule per frame: `trace_log` flush 100x slower
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ai_p2 blocker comp-logging

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128278 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
mapKeys bloom_filter/tokenbf_v1/ngrambf_v1 index prunes rows missing the key
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ai_p2 comp-skip-index

Difficulty 3/5 1-2 days Newbie friendliness 50/100

ClickHouse/ClickHouse#128276 · Opened Oct 30, 2026

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`mapValues` `bloom_filter` throws `BAD_GET`: constant not cast to value type
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ai_p2 comp-skip-index

Difficulty 3/5 1-2 days Newbie friendliness 55/100

ClickHouse/ClickHouse#128275 · 1 comment · Opened Oct 30, 2026

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Skip index on Map `t.a` drops rows matching sibling Map `t.a.key_b`
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ai_p2 comp-skip-index

Difficulty 3/5 1-2 days Newbie friendliness 55/100

ClickHouse/ClickHouse#128274 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
`multiSearchAny` on a map element throws BAD_GET with a mapKeys tokenbf index
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ai_p3 comp-text-index

Difficulty 3/5 1-2 days Newbie friendliness 75/100

ClickHouse/ClickHouse#128273 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Remove low-value local tests and adopt a one-layer-per-behaviour test rule
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rust test-coverage

Difficulty 5/5 Over a week Newbie friendliness 35/100

ClickHouse/clickhousectl#1175 · 1 comment · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Cut local test run time: six tests wait out real timeouts (~70s of ~2m)
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rust test-coverage

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/clickhousectl#1174 · 1 comment · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Finish the clickhouse-cloud-api module split: Query API, large models, test files
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client enhancement rust

Difficulty 4/5 3-5 days Newbie friendliness 48/100

ClickHouse/clickhousectl#1173 · Opened Oct 30, 2026

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[client-v2] Error handling in JSON format
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area:error-handling client-api-v2

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/clickhouse-java#3280 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Restored MaterializedPostgreSQL tables mis-sorted, giving wrong query results
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ai_p3 comp-postgresql

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128271 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Covering-index `INCLUDE` columns in sorting key: DELETE/UPDATE leave stale rows
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ai_p3 comp-postgresql

Difficulty 3/5 1-2 days Newbie friendliness 55/100

ClickHouse/ClickHouse#128270 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
parseDateTime resets month and day when a weekday follows the date
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ai_p2 comp-regular-function

Difficulty 3/5 1-2 days Newbie friendliness 70/100

ClickHouse/ClickHouse#128267 · 1 comment · Opened Oct 30, 2026

Maintainers usually reply within 1 day
toUTCTimestamp is 1 h off near DST transitions
Open
- Is something wrong?
ai_p2 comp-datetime

Difficulty 3/5 1-2 days Newbie friendliness 85/100

ClickHouse/ClickHouse#128266 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Iceberg `OPTIMIZE` sums all live files into `added-records`: `count()` inflated
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ai_p1 comp-datalake

Difficulty 3/5 1-2 days Newbie friendliness 55/100

ClickHouse/ClickHouse#128265 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Iceberg `OPTIMIZE` brings back rows of a dropped partition
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ai_p1 comp-datalake

Difficulty 3/5 1-2 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128264 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Iceberg `OPTIMIZE` writes metadata from scratch: field ids and partition spec lost
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ai_p1 comp-datalake

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128263 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
BSONEachRow writes wrong nested document size when dotted names collide
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ai_p2 comp-formats

Difficulty 3/5 1-2 days Newbie friendliness 70/100

ClickHouse/ClickHouse#128260 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Wrong result: parallel replicas read a materialized view created separately on each replica once per replica
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comp-parallel-replicas

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128254 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Use `advanced` JSON shared data serialization only for parts above a size threshold, not for every merged part
Open
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comp-json-datatype

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128253 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Require specific communication style for agents
Open
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enhancement

Difficulty 3/5 Half a day Newbie friendliness 25/100

ClickHouse/clickhouse-js#1095 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Add a status command that reports CLI, auth, project and skills context in one call
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enhancement

Difficulty 5/5 Over a week Newbie friendliness 35/100

ClickHouse/clickhousectl#1163 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Return next-step polling hints in JSON for asynchronous Cloud operations
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cloud enhancement

Difficulty 4/5 3-5 days Newbie friendliness 52/100

ClickHouse/clickhousectl#1162 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Add a command search so agents can find commands and flags by keyword
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enhancement

Difficulty 5/5 Over a week Newbie friendliness 45/100

ClickHouse/clickhousectl#1161 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Local Postgres container names collide across projects
Open
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bug local

Difficulty 4/5 3-5 days Newbie friendliness 48/100

ClickHouse/clickhousectl#1160 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Pin subcommand order in --help
Open
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enhancement

Difficulty 3/5 1-2 days Newbie friendliness 70/100

ClickHouse/clickhousectl#1158 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Split oversized Cloud domain modules into directories
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cloud enhancement rust

Difficulty 5/5 Over a week Newbie friendliness 35/100

ClickHouse/clickhousectl#1157 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Shell completions: decide how to serve them
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enhancement

Difficulty 5/5 Over a week Newbie friendliness 35/100

ClickHouse/clickhousectl#1155 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Direct Cloud database connections with JWT auth (no password, no Query API key)
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cloud enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

ClickHouse/clickhousectl#1154 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Parquet and Iceberg reads run JOIN runtime filters after weak PREWHERE conditions; running the more selective one first makes TPC-DS q37 and q82 2.1-2.3x faster
Open
- Is something wrong?
comp-parquet-reader-v3 performance

Difficulty 5/5 Over a week Newbie friendliness 10/100

ClickHouse/ClickHouse#128231 · 2 comments · Opened Oct 30, 2026

Maintainers usually reply within 1 day
The filter left in WHERE after a partial move to PREWHERE loses its query condition cache key, so repeated queries read more granules
Open
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comp-query-optimizer performance

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128229 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Iceberg: support add_files and replace_files (register existing data files into a table)
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comp-datalake

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128228 · Opened Oct 30, 2026

Maintainers usually reply within 1 day
Iceberg: support ATTACH PARTITION and REPLACE PARTITION FROM on object-storage tables
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comp-datalake

Difficulty 4/5 3-5 days Newbie friendliness 45/100

ClickHouse/ClickHouse#128227 · Opened Oct 30, 2026

Maintainers usually reply within 1 day

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