Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

Add support for optionally fetching actual remote cost estimates

Open
#129 0 comments 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

Nobody has claimed this yet.

Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
30/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
c, clickhouse, postgresql, sql
Domain
backend, database

Research direction

Start by reviewing pg_clickhouse's current handling of postgres_fdw's use_remote_estimate, then study postgres_fdw's estimate_path_cost_size() logic. Compare that flow with ClickHouse's EXPLAIN ESTIMATE behavior. Done means an optional setting triggers actual remote cost estimates instead of the current no-op.

Written by the indexing model from the issue text.

Description

planner pushdown

Consider supporting actual remote cost estimation. Borrow from postgres_fdw's use_remote_estimate (currently a no-op in pg_clickhouse) to trigger fetching actual estimates. postgres_fdw has logic in its estimate_path_cost_size() function to execute an EXPLAIN on the remote host; perhaps we can do the same with ClickHouse's EXPLAIN ESTIMATE.

Dominant language
C
Stars
284
Forks
21
Avg merge
23h 1m
Merged PRs (30d)
20

Getting set up

We have not checked this project's setup files yet. Start from its README, and see our first-contribution guide for the general steps.

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from ClickHouse/pg_clickhouse

All issues in ClickHouse/pg_clickhouse

Similar issues

More C issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.