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Your First Databend Pull Request

Databend is an open source project, you can help with ideas, code, or documentation, we appreciate any efforts that help us to make the project better!

This document is a short guide for the people who want to contribute to Databend.

Our goal is to make contributing to the Databend project easy and transparent.

Thank you.


Once the code been merged, your name will be stored in the system.contributors table forever.

SELECT * FROM system.contributors


Databend is written in Rust, to build Databend from scratch you will need to install the following tools:

Coding Guidelines

Code Format and Analysis

$ make lint

Code Documentation

Any public fields, functions, and methods should be documented with Rustdoc.

Please follow the conventions as detailed below for modules, structs, enums, and functions. The single line is used as a preview when navigating Rustdoc. As an example, see the 'Structs' and 'Enums' sections in the collections Rustdoc.

/// [Single line] One line summary description
/// [Longer description] Multiple lines, inline code
/// examples, invariants, purpose, usage, etc.
[Attributes] If attributes exist, add after Rustdoc

Example below:

/// Represents (x, y) of a 2-dimensional grid
/// A line is defined by 2 instances.
/// A plane is defined by 3 instances.
struct Point {
x: i32,
y: i32,

Pull Requests

Submit a PR

  1. Fork the databend repo and create your branch from main.
  2. Open a regular issue for binding the pull request.
  3. Submit a Draft Pull Requests, tag your work in progress.
  4. If you have added code that should be tested, add unit tests.
  5. Verify and ensure that the test suites passes, make test.
  6. Make sure your code passes both linters, make lint.
  7. Change the status to “Ready for review”.
  8. Watch out the replies from the @mergify, she will be your guide.

PR Title

Format: <type>(<scope>): <subject>

<scope> is optional

fix(query): fix group by string bug
^--^ ^------------^
| |
| +-> Summary in present tense.
+-------> Type: rfc, feat, fix, refactor, ci, docs, chore

More types:

  • rfc: this PR proposes a new RFC
  • feat: this PR introduces a new feature to the codebase
  • fix: this PR patches a bug in codebase
  • refactor: this PR changes the code base without new features or bugfix
  • ci: this PR changes build/ci steps
  • docs: this PR changes the documents or websites
  • chore: this PR only has small changes that no need to record, like coding styles.

PR Template

Databend has a Pull Request Template:

I hereby agree to the terms of the CLA available at:

## Summary

Summary about this PR

Fixes #issue

You should not change the PR template context, but need to finish:

  • Summary - Describes what constitutes the Pull Request and what changes you have made to the code. For example, fixes which issue.


Unit tests

$ make unit-test

Stateless tests

$ make stateless-test


Databend uses GitHub issues to track bugs. Please include necessary information and instructions to reproduce your issue.


All developer documentation is published on the Databend developer site,

Code of Conduct

Please refer to the Code of Conduct, which describes the expectations for interactions within the community.