ClickHouse/pg_clickhouse

Interfaces to query ClickHouse databases from PostgreSQL

Is ClickHouse/pg_clickhouse beginner-friendly?

The maintainers of ClickHouse/pg_clickhouse usually reply to a pull request within 1 day. No beginner-friendly issue is open right now; the list below has the other issues we hold for it.

Stars: 284
Forks: 21
Open beginner issues: 0
Indexed issues: 35
Avg merge: 23h 1m
Merged PRs (30d): 20

Dominant language: C
License: Apache-2.0
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 15, 2026
Contributing guide: No contributing guide
Code of conduct: No code of conduct
Beginner labels: help wanted

How to contribute to ClickHouse/pg_clickhouse

There is no contributing guide, so start from the README and a few recently merged pull requests to see how changes are proposed.
Your contributions will be published under the project's Apache-2.0 license.
Follow the repository to hear when a new beginner-friendly issue opens, or look through the other issues below.

Beginner friendly Everything

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Issues somebody may already be working on are listed last. List everything by date

Document how to correlate a foreign scan with `system.query_log`
Open
- Is something wrong?
Difficulty 1/5 1-3 hours Newbie friendliness 88/100

ClickHouse/pg_clickhouse#383 · 1 comment · Opened Sep 27, 2026

Maintainers usually reply within 1 day
Add IMPORT FOREIGN SCHEMA options to selectively alter data types
Open
- Is something wrong?
data types enhancement

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

ClickHouse/pg_clickhouse#380 · Opened Sep 25, 2026

Maintainers usually reply within 1 day
Push Down regr_ Functions
Open
- Is something wrong?
enhancement functions pushdown

Difficulty 3/5 1-2 days Newbie friendliness 68/100

ClickHouse/pg_clickhouse#379 · Opened Sep 25, 2026

Maintainers usually reply within 1 day
Push down multidimensional array slice expressions
Open
- Is something wrong?
operators pushdown

Difficulty 3/5 1-2 days Newbie friendliness 65/100

ClickHouse/pg_clickhouse#375 · Opened Sep 23, 2026

Maintainers usually reply within 1 day
Add support for asynchronous fetching, the `async_capable` table option
Open
- Is something wrong?
enhancement planner

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

ClickHouse/pg_clickhouse#294 · 1 comment · Opened Jun 24, 2026

Maintainers usually reply within 1 day
ORDER BY pushdown ignores sort-order semantics mismatch (text collation, UUID) — merge joins fail with "mergejoin input data is out of order", wrong-results risk
Open
- Is something wrong?
bug pushdown

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

ClickHouse/pg_clickhouse#276 · 3 comments · Opened Jun 13, 2026

Maintainers usually reply within 1 day
Push down all JOIN expressions as JOIN expressions
Open
- Is something wrong?
enhancement pushdown

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

ClickHouse/pg_clickhouse#253 · Opened May 15, 2026

Maintainers usually reply within 1 day
Idea: Incorporate ClickHouse ordering into query planner?
Open
- Is something wrong?
enhancement

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

ClickHouse/pg_clickhouse#251 · Opened May 14, 2026

Maintainers usually reply within 1 day
Support JSON/JSONB #> array and #>> array path operators
Open
- Is something wrong?
data types operators

Difficulty 3/5 1-2 days Newbie friendliness 68/100

ClickHouse/pg_clickhouse#248 · 1 comment · Opened May 11, 2026

Maintainers usually reply within 1 day
Add Upgrade Test
Open
- Is something wrong?
quality workflow

Difficulty 4/5 3-5 days Newbie friendliness 55/100

ClickHouse/pg_clickhouse#243 · Opened May 8, 2026

Maintainers usually reply within 1 day
Add column case option to IMPORT FOREIGN SCHEMA
May be free again @serprex claimed this 38 days ago, and no pull request is open. Open
- Is something wrong?
enhancement sql

ClickHouse/pg_clickhouse#236 · 1 assignee · Opened May 8, 2026

Maintainers usually reply within 1 day
Test Against misbehaving Mock ClickHouse
Open
- Is something wrong?
help wanted quality

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

ClickHouse/pg_clickhouse#194 · Opened Apr 7, 2026

Maintainers usually reply within 1 day
Map All Postgres Operators
Open
- Is something wrong?
enhancement functions pushdown sql

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

ClickHouse/pg_clickhouse#168 · Opened Apr 1, 2026

Maintainers usually reply within 1 day
Support JSONB Subscripting
Open
- Is something wrong?
data types enhancement pushdown

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

ClickHouse/pg_clickhouse#166 · Opened Apr 1, 2026

Maintainers usually reply within 1 day
Test and if necessary repair issues inserting `NULL` to get a default value when a column has an explicit `DEFAULT`
Open
- Is something wrong?
data types drivers

Difficulty 4/5 3-5 days Newbie friendliness 38/100

ClickHouse/pg_clickhouse#148 · Opened Feb 5, 2026

Maintainers usually reply within 1 day
EXPLAIN VERBOSE "FDW Time" does not look right
Open
- Is something wrong?
benchmarks bug quality

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

ClickHouse/pg_clickhouse#144 · Opened Feb 3, 2026

Maintainers usually reply within 1 day
Improve Cost Discrimination for Aggregate Queries
Open
- Is something wrong?
planner pushdown

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

ClickHouse/pg_clickhouse#132 · Opened Jan 21, 2026

Maintainers usually reply within 1 day
Implement the `AnalyzeForeignTable` Callback
Open
- Is something wrong?
enhancement planner

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

ClickHouse/pg_clickhouse#131 · Opened Jan 21, 2026

Maintainers usually reply within 1 day
Add support for optionally fetching actual remote cost estimates
Open
- Is something wrong?
planner pushdown

Difficulty 5/5 Over a week Newbie friendliness 30/100

ClickHouse/pg_clickhouse#129 · Opened Jan 21, 2026

Maintainers usually reply within 1 day
Feature Request: Create extension container image for e.g. CNPG
Open
- Is something wrong?
distribution

Difficulty 4/5 3-5 days Newbie friendliness 38/100

ClickHouse/pg_clickhouse#96 · 1 comment · Opened Dec 14, 2025

Maintainers usually reply within 1 day
Decide how to handle Aggregate function combinators
Open
- Is something wrong?
aggregates functions interfaces pushdown sql

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

ClickHouse/pg_clickhouse#88 · Opened Dec 10, 2025

Maintainers usually reply within 1 day
Add version verification script/workflow
Open
- Is something wrong?
distribution quality

Difficulty 3/5 1-2 days Newbie friendliness 48/100

ClickHouse/pg_clickhouse#86 · Opened Dec 10, 2025

Maintainers usually reply within 1 day
Add support for pushdown of UNION queries when they all query the remote
Open
- Is something wrong?
enhancement pushdown

Difficulty 5/5 Over a week Newbie friendliness 30/100

ClickHouse/pg_clickhouse#85 · Opened Dec 10, 2025

Maintainers usually reply within 1 day
Add Session Settings to `FOREIGN SERVER`s and `USER MAPPING`s
Open
- Is something wrong?
enhancement interfaces sql

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

ClickHouse/pg_clickhouse#83 · Opened Dec 10, 2025

Maintainers usually reply within 1 day
Get the remaining 10 un-pushed-down TPC-H queries optimally planned
May be free again @JoshDreamland claimed this 121 days ago, and no pull request is open. Open
- Is something wrong?
benchmarks pushdown

ClickHouse/pg_clickhouse#81 · 2 assignees · Opened Dec 10, 2025

Maintainers usually reply within 1 day
Improve Subquery Joins
May be free again @JoshDreamland claimed this 121 days ago, and no pull request is open. Open
- Is something wrong?
pushdown

ClickHouse/pg_clickhouse#79 · 1 comment · 2 assignees · Opened Dec 10, 2025

Maintainers usually reply within 1 day
Improve SEMI JOIN testing and behaviors
May be free again @JoshDreamland claimed this 38 days ago, and no pull request is open. Open
- Is something wrong?
pushdown

ClickHouse/pg_clickhouse#62 · 1 assignee · Opened Dec 1, 2025

Maintainers usually reply within 1 day
Support All Data Types
May be free again @serprex claimed this 38 days ago, and no pull request is open. Open
- Is something wrong?
data types enhancement

ClickHouse/pg_clickhouse#49 · 2 comments · 1 reaction · 1 assignee · Opened Nov 19, 2025

Maintainers usually reply within 1 day
Convince Aggregates to return NULL instead of NaN
Open
- Is something wrong?
aggregates enhancement help wanted

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

ClickHouse/pg_clickhouse#42 · Opened Nov 12, 2025

Maintainers usually reply within 1 day
Support `UPDATE`, `DELETE`
Open
- Is something wrong?
enhancement sql

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

ClickHouse/pg_clickhouse#30 · 1 reaction · Opened Nov 3, 2025

Maintainers usually reply within 1 day
Push down joins against an aggregated `IN (SELECT … GROUP BY … HAVING)` subquery (TPC-H Q18 shape)
Possibly taken @JoshDreamland claimed this 2 days ago. Open
- Is something wrong?
enhancement pushdown sql

ClickHouse/pg_clickhouse#378 · 1 assignee · Opened Sep 25, 2026

Maintainers usually reply within 1 day
Nested Type Issues
Possibly taken @serprex claimed this 5 days ago. Open
- Is something wrong?
bug data types

ClickHouse/pg_clickhouse#372 · 7 comments · 2 assignees · Opened Sep 22, 2026

Maintainers usually reply within 1 day

ClickHouse/pg_clickhouse

Is ClickHouse/pg_clickhouse beginner-friendly?

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