docs/source/contributor-guide/roadmap.md - datafusion - Git at Google

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 # Roadmap and Improvement Proposals

 The [project introduction](../user-guide/introduction) explains the
 overview and goals of DataFusion, and our development efforts largely
 align to that vision.

 ## Planning `EPIC`s

 DataFusion uses [GitHub issues] to track planned work. We collect related
 tickets using tracking issues marked with the `EPIC` label, containing
 discussion and links to more detailed items:

 [github issues]: https://github.com/apache/datafusion/issues

 - [The current list of `EPIC`s can be found here.](https://github.com/apache/datafusion/issues?q=is%3Aissue%20state%3Aopen%20label%3AEPIC)

 - [The current list of `PROPOSAL EPIC` (that are not yet underway) can be found here.](https://github.com/apache/datafusion/issues?q=is%3Aissue%20state%3Aopen%20label%3A%22PROPOSAL%20EPIC%22)

 Epics offer a high level roadmap of what the DataFusion community is thinking
 about. The epics are not meant to restrict possibilities, but rather help
 organize the community and make it easier to see where development is headed,
 align our work, and inspire additional contributions.

 We also welcome contributions for items not covered by epics. However, before
 submitting a large PR, we strongly suggest and request you start a conversation as described in [Discussing New Features](#discussing-new-features) below.

 [dev@arrow.apache.org]: mailto:dev@arrow.apache.org

 ## Quarterly Roadmap

 The DataFusion roadmap is driven by the priorities of contributors rather than
 any single organization or coordinating committee. We typically discuss our
 roadmap using GitHub issues, approximately quarterly, and invite you to join the
 discussion.

 For more information:

 1. [Search for issues labeled `roadmap`](https://github.com/apache/datafusion/issues?q=is%3Aissue%20%20%20roadmap)
 2. [DataFusion Road Map: Q1 2026](https://github.com/apache/datafusion/issues/18494)
 3. [DataFusion Road Map: Q3-Q4 2025](https://github.com/apache/datafusion/issues/15878)
 4. [2024 Q4 / 2025 Q1 Roadmap](https://github.com/apache/datafusion/issues/13274)

 ## Improvement Proposals

 ### Discussing New Features

 If you plan to work on a new feature that doesn't have an existing ticket, it is
 a good idea to open one for discussion. Advanced discussion helps avoid wasted
 effort by determining if the feature is a good fit for DataFusion before too
 much time is invested. Discussion on a ticket can help gather feedback from the
 community and is likely easier to discuss than a 1000 line PR.

 Maintainers will mark major proposals as `PROPOSED EPIC` to make them more
 visible, but we are very limited on review bandwidth. If you open a ticket and it
 doesn't get any response, try `@`-mentioning recently active community members
 in the ticket, or [posting to the mailing list or Discord](communication.md).

 ### Supervising Maintainers

 We have found that most successful epics have one or more "supervising
 maintainers", a committer ([see here for current list]) who take the lead on
 reviewing and committing PRs, helps with design, and coordinates and
 communicates with the community. If you want to ship a large feature, we
 recommend finding such maintainer upfront; otherwise, your PRs may
 remain unreviewed for a very long time.

 Supervising maintainers have no additional formal authority and there is
 currently no formal process for appointing, approving or tracking who has that
 role for a given epic. Instead, we rely on discussion on the ticket or PR.
 Helping complete an epic is a significant time commitment, so maintainers are
 more likely to help features they are particularly interested in or align with
 their own project's use of DataFusion.

 If you are willing to be a supervising maintainer for a feature, please say so
 explicitly. If you are unsure, we suggest asking directly who is willing to take
 the role, as it can be hard to tell sometimes whether a committer is simply
 participating and giving general feedback.

 [see here for current list]: governance.md

 ### What Contributions are Good Fits?

 DataFusion is designed to be highly extensible, and many features can be
 implemented as extensions without changes or additions to the core. Support for
 new functions, data formats, and similar functionality can be added using those
 extension APIs, and there are already many existing community supported
 extensions listed in the [extensions list].

 Query engines are complex pieces of software to develop and maintain. Given our
 limited maintenance bandwidth, we try to keep the DataFusion core as simple and
 focused as possible, while still satisfying the [design goal] of an easy to
 start initial experience.

 With that in mind, contributions that meet the following criteria are more likely
 to be accepted:

 1. Bug fixes for existing features
 2. Test coverage for existing features
 3. Documentation improvements / examples
 4. Performance improvements to existing features (with benchmarks)
 5. "Small" functional improvements to existing features (if they don't change existing behavior)
 6. Additional APIs for extending DataFusion's capabilities
 7. CI improvements

 Contributions that will likely involve more discussion (see Discussing New
 Features above) prior to acceptance include:

 1. Major new functionality (even if it is part of the "standard SQL")
 2. New functions, especially if they aren't part of "standard SQL"
 3. New data sources (e.g. support for Apache ORC)

 [extensions list]: ../library-user-guide/extensions.md
 [design goal]: https://docs.rs/datafusion/latest/datafusion/index.html#design-goals

 ### Design Build vs. Big Up Front Design

 Typically, the DataFusion community attacks large problems by solving them bit
 by bit and refining a solution iteratively on the `main` branch as a series of
 Pull Requests. This is different from projects which front-load the effort
 with a more comprehensive design process.

 By "advancing the front" the community always makes tangible progress, and the strategy is
 especially effective in a project that relies on individual contributors who may
 not have the time or resources to invest in a large upfront design effort.
 However, this "bit by bit approach" doesn't always succeed, and sometimes we get
 stuck or go down the wrong path and then change directions.

 Our process necessarily results in imperfect solutions being the "state of the
 code" in some cases, and larger visions are not yet fully realized. However, the
 community is good at driving things to completion in the long run. If you see
 something that needs improvement or an area that is not yet fully realized,
 please consider submitting an issue or PR to improve it. We are always looking
 for more contributions.
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	to you under the Apache License, Version 2.0 (the
	"License"); you may not use this file except in compliance
	with the License. You may obtain a copy of the License at

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	Unless required by applicable law or agreed to in writing,
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	KIND, either express or implied. See the License for the
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	under the License.
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	# Roadmap and Improvement Proposals

	The [project introduction](../user-guide/introduction) explains the
	overview and goals of DataFusion, and our development efforts largely
	align to that vision.

	## Planning `EPIC`s

	DataFusion uses [GitHub issues] to track planned work. We collect related
	tickets using tracking issues marked with the `EPIC` label, containing
	discussion and links to more detailed items:

	[github issues]: https://github.com/apache/datafusion/issues

	- [The current list of `EPIC`s can be found here.](https://github.com/apache/datafusion/issues?q=is%3Aissue%20state%3Aopen%20label%3AEPIC)

	- [The current list of `PROPOSAL EPIC` (that are not yet underway) can be found here.](https://github.com/apache/datafusion/issues?q=is%3Aissue%20state%3Aopen%20label%3A%22PROPOSAL%20EPIC%22)

	Epics offer a high level roadmap of what the DataFusion community is thinking
	about. The epics are not meant to restrict possibilities, but rather help
	organize the community and make it easier to see where development is headed,
	align our work, and inspire additional contributions.

	We also welcome contributions for items not covered by epics. However, before
	submitting a large PR, we strongly suggest and request you start a conversation as described in [Discussing New Features](#discussing-new-features) below.

	[dev@arrow.apache.org]: mailto:dev@arrow.apache.org

	## Quarterly Roadmap

	The DataFusion roadmap is driven by the priorities of contributors rather than
	any single organization or coordinating committee. We typically discuss our
	roadmap using GitHub issues, approximately quarterly, and invite you to join the
	discussion.

	For more information:

	1. [Search for issues labeled `roadmap`](https://github.com/apache/datafusion/issues?q=is%3Aissue%20%20%20roadmap)
	2. [DataFusion Road Map: Q1 2026](https://github.com/apache/datafusion/issues/18494)
	3. [DataFusion Road Map: Q3-Q4 2025](https://github.com/apache/datafusion/issues/15878)
	4. [2024 Q4 / 2025 Q1 Roadmap](https://github.com/apache/datafusion/issues/13274)

	## Improvement Proposals

	### Discussing New Features

	If you plan to work on a new feature that doesn't have an existing ticket, it is
	a good idea to open one for discussion. Advanced discussion helps avoid wasted
	effort by determining if the feature is a good fit for DataFusion before too
	much time is invested. Discussion on a ticket can help gather feedback from the
	community and is likely easier to discuss than a 1000 line PR.

	Maintainers will mark major proposals as `PROPOSED EPIC` to make them more
	visible, but we are very limited on review bandwidth. If you open a ticket and it
	doesn't get any response, try `@`-mentioning recently active community members
	in the ticket, or [posting to the mailing list or Discord](communication.md).

	### Supervising Maintainers

	We have found that most successful epics have one or more "supervising
	maintainers", a committer ([see here for current list]) who take the lead on
	reviewing and committing PRs, helps with design, and coordinates and
	communicates with the community. If you want to ship a large feature, we
	recommend finding such maintainer upfront; otherwise, your PRs may
	remain unreviewed for a very long time.

	Supervising maintainers have no additional formal authority and there is
	currently no formal process for appointing, approving or tracking who has that
	role for a given epic. Instead, we rely on discussion on the ticket or PR.
	Helping complete an epic is a significant time commitment, so maintainers are
	more likely to help features they are particularly interested in or align with
	their own project's use of DataFusion.

	If you are willing to be a supervising maintainer for a feature, please say so
	explicitly. If you are unsure, we suggest asking directly who is willing to take
	the role, as it can be hard to tell sometimes whether a committer is simply
	participating and giving general feedback.

	[see here for current list]: governance.md

	### What Contributions are Good Fits?

	DataFusion is designed to be highly extensible, and many features can be
	implemented as extensions without changes or additions to the core. Support for
	new functions, data formats, and similar functionality can be added using those
	extension APIs, and there are already many existing community supported
	extensions listed in the [extensions list].

	Query engines are complex pieces of software to develop and maintain. Given our
	limited maintenance bandwidth, we try to keep the DataFusion core as simple and
	focused as possible, while still satisfying the [design goal] of an easy to
	start initial experience.

	With that in mind, contributions that meet the following criteria are more likely
	to be accepted:

	1. Bug fixes for existing features
	2. Test coverage for existing features
	3. Documentation improvements / examples
	4. Performance improvements to existing features (with benchmarks)
	5. "Small" functional improvements to existing features (if they don't change existing behavior)
	6. Additional APIs for extending DataFusion's capabilities
	7. CI improvements

	Contributions that will likely involve more discussion (see Discussing New
	Features above) prior to acceptance include:

	1. Major new functionality (even if it is part of the "standard SQL")
	2. New functions, especially if they aren't part of "standard SQL"
	3. New data sources (e.g. support for Apache ORC)

	[extensions list]: ../library-user-guide/extensions.md
	[design goal]: https://docs.rs/datafusion/latest/datafusion/index.html#design-goals

	### Design Build vs. Big Up Front Design

	Typically, the DataFusion community attacks large problems by solving them bit
	by bit and refining a solution iteratively on the `main` branch as a series of
	Pull Requests. This is different from projects which front-load the effort
	with a more comprehensive design process.

	By "advancing the front" the community always makes tangible progress, and the strategy is
	especially effective in a project that relies on individual contributors who may
	not have the time or resources to invest in a large upfront design effort.
	However, this "bit by bit approach" doesn't always succeed, and sometimes we get
	stuck or go down the wrong path and then change directions.

	Our process necessarily results in imperfect solutions being the "state of the
	code" in some cases, and larger visions are not yet fully realized. However, the
	community is good at driving things to completion in the long run. If you see
	something that needs improvement or an area that is not yet fully realized,
	please consider submitting an issue or PR to improve it. We are always looking
	for more contributions.