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About this site

This site is the official documentation for kdb+ and the q programming language.

It reflects the work of the KX community since 1993, has many authors, and continues to evolve.

This site is a project of the KX Librarian:

A librarian’s job is to put information where people can find it.

The Search Box on this site is customized for the q language. Some examples:

Operator glyphs            $  ^  .  <>  /:  ':
 and their names           dollar  bang  at
Operator names             Drop  roll  Enum Extend  
Keywords                   xbar  like  ajf0  uj
Namespace objects          .z.pd  .Q.dpfts
System commands            \d  \ts  \_  \\
Command-line options       -b  -p
Internal functions         -11!
Popular queries            types  datatypes

Queries not matched by the Search Box are handled by Google Search.

Install man.q to open the Reference direct from the q session.




Truncated GitHub URLs are prefixed with the GitHub icon and omit the prefix.

For example, read KxSystems/kdb as

Download is a copy of the site you can run from your filesystem.


A finished work is exactly that, requires resurrection.
John Cage, “Lecture on Nothing”, 1949

The repository for this site is KxSystems/docs. The contribution model is GitHub and Forking Workflow. To contribute, submit a pull request.

The repo includes a style guide for contributors.

We gratefully acknowledge pull requests from

Alexander Belopolsky            kylenarocroc
Aleks Bunin                     Sean Keevey
Angus Wilson                    Sean O’Hagan
Andrew in New York              Rian O’Cuinneagain
Chris Shucksmith                Rikesh
Cillian Reilly                  Thomas Smyth
Conor McCarthy                  Sergey Vidyuk
David Z. Han                    Simon Shanks
Esperanza Lopez Aguilera        Vincent Bernardoff
Geo Carncross                   William Da Silva
James Hanna


This work is licensed under a Creative Commons Attribution 4.0 International License.


This site includes images for which KX holds neither copyright nor permission. These images serve as links to their original sites. We understand this to be fair use.

If you are a copyright holder and object to this use, please write to


In 2018 and 2019 we made changes to the terminology used to describe the q language.


How to cite the q programming language:

Bibtex format

    author= {{Kx Systems, Inc.}},
    year  = {2020},
    title = {Documentation for kdb+ and q},
    note  = {\url{}, 
             Last accessed on 2020-04-15},
Chicago style

“Reference Card.” Documentation for kdb and q . Kx Systems, Inc. Accessed April 15, 2020.

Harvard style

Documentation for kdb+ and q. 2020. Reference Card. [online] Available at: [Accessed 15 April 2020].

Vancouver style

Reference Card [Internet]. Documentation for kdb and q. Kx Systems, Inc.; 2020 [cited 2020Apr15]. Available from:

Citation Machine for other citation styles


The KX wiki was the primary documentation for q and kdb+ until January 2017.

The content, which runs on Mediawiki, has been archived on GitHub.