+1 for Andrew's proposal.

On Sat, Sep 5, 2026 at 1:56 AM Kevin Liu <[email protected]> wrote:

> + dev@iceberg
>
> (lesson learned, emailing 2 devlist might not be the best idea logistically
> haha)
>
> On Fri, Sep 4, 2026 at 10:48 AM Kevin Liu <[email protected]> wrote:
>
> > Thanks for all the great discussions so far. I'm glad we found a solution
> > that benefits the broader ecosystem.
> > I'm +1 to moving to an apache-governed location,
> > apache/datafusion-iceberg seems like a great place. I like the process
> > Andrew proposed, happy to help with the logistics.
> >
> > Best,
> > Kevin Liu
> >
> > PS I have also removed the iceberg python binding that exports
> > DataFusion's TableProvider, so that's 1 less thing we have to worry
> about.
> >  https://github.com/apache/iceberg-rust/issues/3036
> >
> > On Fri, Sep 4, 2026 at 6:28 AM Gabriel Musat <[email protected]>
> wrote:
> >
> >> Sounds like a good direction, +1 (non binding)
> >>
> >> I can help porting the commit history of the DataFusion-Iceberg
> >> integration to the new repo if PMCs agree.
> >>
> >> On 2026/09/04 12:27:30 Andrew Lamb wrote:
> >> > I think this is a great idea as well -- thank you for bringing it up
> and
> >> > for the great discussions so far.
> >> >
> >> > While at VLDB this past week, I spoke to at least three people from
> >> > companies adding Apache Iceberg support to their products. All of them
> >> had
> >> > to fork iceberg-rust for one reason or another.
> >> >
> >> > I think we have a huge need to improve our ability to work together
> and
> >> > accelerate everyone's efforts. Giving the DataFusion integration
> access
> >> to
> >> > more expert maintainers with bandwidth I think will help everyone.
> >> >
> >> > There seems to be consensus that we should move the integration code
> to
> >> > DataFusion governance, and that it should remain in the ASF, though
> some
> >> > open technical questions remain.
> >> >
> >> > If that is the case, I propose the following specific process:
> >> > 1. Create the new gitub repository in Apache for the code (e.g.
> >> > apache/datafusion-iceberg)
> >> > 2. Create a PR in the new repo with the proposed code
> >> > 3. Hold a formal vote on the iceberg dev list to move the integration
> >> code
> >> > to DataFusion
> >> > 4. Hold a formal vote on the DataFusion dev list to accept the new
> code
> >> >
> >> > I am happy to help with the logistics (e.g. ASF INFRA ticket to create
> >> the
> >> > new repo, votes, etc) but I am not expert enough to create the
> proposed
> >> PR.
> >> >
> >> > Please let me know your thoughts,
> >> > Andrew
> >> > (PMC Chair of DataFusion)
> >> >
> >> > On Tue, Sep 1, 2026 at 9:48 PM Renjie Liu <[email protected]>
> >> wrote:
> >> >
> >> > > To add more background about the relationship between comet and
> >> datafusion
> >> > > for those who are not familiar with them.
> >> > >
> >> > > Apache datafusion is a popular extensible compute engine written in
> >> rust.
> >> > > Apache comet is an apache spark accelerator builton on apache
> >> datafusion,
> >> > > and also a subproject of apache datafusion.
> >> > >
> >> > > datafusion-iceberg is an apache datafusion extension built on
> >> iceberg-rust,
> >> > > and comet's iceberg support is built on it.
> >> > >
> >> > > On Tue, Sep 1, 2026 at 9:39 PM Andy Grove <[email protected]>
> >> wrote:
> >> > >
> >> > > > +1 for moving to DataFusion PMC. The iceberg-datafusion
> integration
> >> is
> >> > > > very important for Comet.
> >> > > >
> >> > > > On Mon, Aug 31, 2026 at 11:42 PM Xuanwo <[email protected]>
> wrote:
> >> > > > >
> >> > > > > TBH, I also support moving to the DataFusion PMC.
> >> > > > >
> >> > > > > - DataFusion is the largest dependency in iceberg-datafusion.
> >> > > > > - The largest downstream user of iceberg-datafusion is Comet,
> >> which
> >> > > > shares many of the same PMC members as DataFusion.
> >> > > > >
> >> > > > > It feels natural to be part of the DataFusion PMC. As long as DF
> >> PMC is
> >> > > > willing to accept this project, it LGTM.
> >> > > > >
> >> > > > > On Tue, Sep 1, 2026, at 12:03, Renjie Liu wrote:
> >> > > > >
> >> > > > > I don't think the testing should be a blocker of moving
> >> > > > iceberg-datafusion out of iceberg-rust repo. From what I learn,
> >> most of
> >> > > the
> >> > > > sqllogictests are in pr of modifying iceberg-datafusion
> integration,
> >> > > there
> >> > > > are only few cases where we rely on sqllogictests to verify
> >> features.
> >> > > > >
> >> > > > > > How would that sound for the `iceberg-rust` community to
> grant a
> >> > > > couple of Apache DataFusion PMCs committer access to the
> repository,
> >> > > > limited to the `iceberg-datafusion` crate via a CODEOWNERS file,
> so
> >> that
> >> > > > they can help push reviews and PRs forward independently?
> >> > > > >
> >> > > > > I'm not sure if this is feasible, but moving the
> >> iceberg-datafusion
> >> > > > crate to apache datafusion project sounds a more reasonable
> >> approach to
> >> > > me.
> >> > > > It's still governed by Apache, and most of the code is related to
> >> > > > DataFusion, so I think the DataFusion community is in a better
> >> position
> >> > > to
> >> > > > define the vision and design for it.
> >> > > > >
> >> > > > > On Mon, Aug 31, 2026 at 10:45 PM Gabriel Musat <
> >> [email protected]>
> >> > > > wrote:
> >> > > > >
> >> > > > > Hi everyone,
> >> > > > >
> >> > > > > Based on these two facts:
> >> > > > > - There's a current reviewer bandwidth problem that hurts
> >> development
> >> > > > velocity of the `iceberg-datafusion` crate currently hosted under
> >> > > > `apache/iceberg-rust`.
> >> > > > > - There is value in maintaining the `iceberg-datafusion` crate
> >> inside
> >> > > > `apache/iceberg-rust` for testing, design and governance.
> >> > > > >
> >> > > > > How would that sound for the `iceberg-rust` community to grant a
> >> couple
> >> > > > of Apache DataFusion PMCs committer access to the repository,
> >> limited to
> >> > > > the `iceberg-datafusion` crate via a CODEOWNERS file, so that they
> >> can
> >> > > help
> >> > > > push reviews and PRs forward independently?
> >> > > > >
> >> > > > > Based on review history, I'd propose Matt Butrovich and Tim
> >> Saucer as
> >> > > > two good candidates, but this would be completely up to the
> >> > > `iceberg-rust`
> >> > > > community.
> >> > > > >
> >> > > > > On 2026/08/26 17:56:19 Shawn Chang wrote:
> >> > > > > > Hi all,
> >> > > > > >
> >> > > > > > Summarizing the discussion so far, including a few points
> >> raised in
> >> > > > today’s
> >> > > > > > community sync.
> >> > > > > >
> >> > > > > > There seems to be general agreement that the current
> DataFusion
> >> > > > integration
> >> > > > > > has a velocity/reviewer bandwidth problem, and moving it to a
> >> > > separate
> >> > > > > > repository could help DataFusion contributors iterate more
> >> > > > independently.
> >> > > > > > At the same time, several open questions remain:
> >> > > > > >
> >> > > > > >    -
> >> > > > > >
> >> > > > > >    Whether repo separation is the right solution, versus
> >> expanding
> >> > > > > >    DataFusion reviewer/committer participation in
> iceberg-rust.
> >> > > > > >    -
> >> > > > > >
> >> > > > > >    Where the boundary should be between engine specific
> >> integration
> >> > > and
> >> > > > > >    Iceberg core functionality, and how to avoid duplicated or
> >> forked
> >> > > > Iceberg
> >> > > > > >    implementations. (how to avoid the case where
> >> Iceberg-datafusion
> >> > > > moving
> >> > > > > >    much faster than the core and eventually need a forked core
> >> API
> >> > > > > >    implementation)
> >> > > > > >    -
> >> > > > > >
> >> > > > > >    How compatibility and end-to-end correctness testing should
> >> work
> >> > > > across
> >> > > > > >    repositories, since iceberg-rust still relies on DataFusion
> >> for
> >> > > > integration
> >> > > > > >    testing.
> >> > > > > >    -
> >> > > > > >
> >> > > > > >    Where the integration should live and how to keep it under
> >> Apache
> >> > > > > >    governance while making it easy for both Iceberg and
> >> DataFusion
> >> > > > > >    contributors to maintain.
> >> > > > > >
> >> > > > > > So I think the main question is not only whether to move the
> >> code,
> >> > > but
> >> > > > how
> >> > > > > > to improve development velocity without losing the close
> design,
> >> > > > testing,
> >> > > > > > and governance relationship between the engine integration and
> >> > > > iceberg-rust
> >> > > > > > core.
> >> > > > > >
> >> > > > > >
> >> > > > > > Best,
> >> > > > > >
> >> > > > > > Shawn
> >> > > > > >
> >> > > > > > On Mon, Aug 24, 2026 at 4:14 AM Manu Zhang <
> >> [email protected]>
> >> > > > wrote:
> >> > > > > >
> >> > > > > > > +1 moving the DataFusion integration and tests into a
> separate
> >> > > > > > > apache-governed repository. Can we bring this discussion to
> >> the
> >> > > > Community
> >> > > > > > > Sync[1] this week?
> >> > > > > > >
> >> > > > > > > 1.
> >> > > > > > >
> >> > > >
> >> > >
> >>
> https://docs.google.com/document/d/1YuGhUdukLP5gGiqCbk0A5_Wifqe2CZWgOd3TbhY3UQg/edit?tab=t.0
> >> > > > > > >
> >> > > > > > > On Mon, Aug 24, 2026 at 3:37 PM Renjie Liu <
> >> > > [email protected]>
> >> > > > > > > wrote:
> >> > > > > > >
> >> > > > > > >> Hi, Matt:
> >> > > > > > >>
> >> > > > > > >> Thanks for raising this.
> >> > > > > > >>
> >> > > > > > >> 1) Apache governance:
> >> > > > > > >>
> >> > > > > > >> I would +1 for putting this in an apache repo, for example
> a
> >> sub
> >> > > > repo of
> >> > > > > > >> datafusion project. Shawn has stated most of the reasons,
> so
> >> I
> >> > > > don't want
> >> > > > > > >> to repeat it again.
> >> > > > > > >>
> >> > > > > > >> 2) Where do tests live/how tests should be maintained?
> >> > > > > > >>
> >> > > > > > >> Initially I was thinking about putting sqllogictest in
> >> > > > iceberg-rust, but
> >> > > > > > >> after second thought I'm leaning towards to put it in the
> >> new repo
> >> > > > for two
> >> > > > > > >> reasons:
> >> > > > > > >> 1. It would be easier for developer of the
> datafusion-iceberg
> >> > > > integration
> >> > > > > > >> to add tests
> >> > > > > > >> 2. It would make the dependency graph and version release
> >> easier.
> >> > > > Though
> >> > > > > > >> the dependency is on crate level rather than repo level,
> the
> >> > > > bi-direction
> >> > > > > > >> dependency may make version management weird and difficult.
> >> > > > > > >>
> >> > > > > > >> The downside of this approach is that it's a little
> >> unfriendly for
> >> > > > > > >> iceberg-rust developers, but I think it's less frequent for
> >> > > > iceberg-rust
> >> > > > > > >> developers to add sqllogictests compared with
> >> datafusion-iceberg
> >> > > > developers.
> >> > > > > > >>
> >> > > > > > >> 3) Dropping DataFusion dependencies from pyiceberg-core
> >> binding
> >> > > > > > >>
> >> > > > > > >> I'm not quite familiar with this part, but it sounds
> >> reasonable to
> >> > > > me.
> >> > > > > > >>
> >> > > > > > >>
> >> > > > > > >> On Sat, Aug 22, 2026 at 6:50 AM Shawn Chang <
> >> > > [email protected]
> >> > > > >
> >> > > > > > >> wrote:
> >> > > > > > >>
> >> > > > > > >>> Hi Matt,
> >> > > > > > >>>
> >> > > > > > >>> Thanks for raising this! I generally agree that we can
> move
> >> the
> >> > > > > > >>> datafusion
> >> > > > > > >>> integration to a separate repo if that helps more
> DataFusion
> >> > > > experts to
> >> > > > > > >>> work on the integrations
> >> > > > > > >>>
> >> > > > > > >>> On the three considerations:
> >> > > > > > >>> 1) Apache governance:
> >> > > > > > >>> I think this is my biggest concern so far. This could not
> >> only
> >> > > > affect
> >> > > > > > >>> contributors, but also whether the downstream users could
> >> > > continue
> >> > > > to use
> >> > > > > > >>> the integration.
> >> > > > > > >>> Even if the code remains Apache-licensed, governance,
> >> release of
> >> > > > > > >>> artifacts,
> >> > > > > > >>> and contribution policies can matter for adoption.
> >> > > > > > >>> We should explore more about the option to keep it under
> an
> >> > > > > > >>> Apache-governed
> >> > > > > > >>> repository.
> >> > > > > > >>>
> >> > > > > > >>> 2) Where do tests live/how tests should be maintained?
> >> > > > > > >>>
> >> > > > > > >>> I think this is closely related to the governance
> question.
> >> To
> >> > > me,
> >> > > > the
> >> > > > > > >>> broader question is: *how do we make it easy for people
> >> from both
> >> > > > the
> >> > > > > > >>> Iceberg Rust and DataFusion communities to maintain the
> >> > > > integration?*
> >> > > > > > >>>
> >> > > > > > >>> If we move it to a non-Apache repository, I worry that it
> >> could
> >> > > > > > >>> eventually
> >> > > > > > >>> look somewhat like the current Iceberg Java <> Trino
> >> integration:
> >> > > > the
> >> > > > > > >>> integration primarily lives on the Trino side and is
> >> therefore
> >> > > > mostly
> >> > > > > > >>> maintained by people who are already deeply involved in
> >> Trino.
> >> > > > > > >>>
> >> > > > > > >>> There is an important difference here, though. For Iceberg
> >> Java,
> >> > > > Spark is
> >> > > > > > >>> arguably the primary engine integration and has a large
> >> Iceberg
> >> > > > > > >>> contributor
> >> > > > > > >>> base around it, so having the Trino integration maintained
> >> more
> >> > > > > > >>> independently is relatively natural. In Iceberg Rust
> today,
> >> > > > DataFusion
> >> > > > > > >>> has
> >> > > > > > >>> a much more central role. It is by far the most mature
> >> engine
> >> > > > integration
> >> > > > > > >>> in the project, is used by our SQLLogicTest
> infrastructure,
> >> and
> >> > > > many
> >> > > > > > >>> users
> >> > > > > > >>> building on Iceberg Rust are also building on DataFusion.
> >> The
> >> > > > overlap
> >> > > > > > >>> between the two communities is therefore much larger.
> >> > > > > > >>>
> >> > > > > > >>> Because of that, I would prefer that extracting the
> >> integration
> >> > > > does not
> >> > > > > > >>> turn it into something that is effectively owned only by
> the
> >> > > > DataFusion
> >> > > > > > >>> side. Ideally, both Iceberg Rust contributors and
> DataFusion
> >> > > > contributors
> >> > > > > > >>> should be able to review changes, maintain compatibility,
> >> and
> >> > > > evolve the
> >> > > > > > >>> integration together.
> >> > > > > > >>>
> >> > > > > > >>> 3) Dropping DataFusion dependencies from pyiceberg-core
> >> binding:
> >> > > I
> >> > > > think
> >> > > > > > >>> it
> >> > > > > > >>> makes sense to make things simpler and have left a comment
> >> on the
> >> > > > github
> >> > > > > > >>> issue with more detailed thoughts:
> >> > > > > > >>> https://github.com/apache/iceberg-rust/issues/3036
> >> > > > > > >>>
> >> > > > > > >>> Best,
> >> > > > > > >>> Shawn
> >> > > > > > >>>
> >> > > > > > >>> On Fri, Aug 21, 2026 at 11:23 AM Matt Butrovich <
> >> > > > [email protected]>
> >> > > > > > >>> wrote:
> >> > > > > > >>>
> >> > > > > > >>> > Hello all,
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > I've never tried emailing two different project lists at
> >> once,
> >> > > > but it
> >> > > > > > >>> was
> >> > > > > > >>> > suggested that I do so to try to track the conversation
> >> across
> >> > > > both
> >> > > > > > >>> > communities. We'll see how this threads on the mailing
> >> lists.
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > There has been a GitHub Discussion
> >> > > > > > >>> >
> >> > > > > > >>>
> >> > > >
> >> > >
> >>
> https://github.com/apache/iceberg-rust/discussions/2992#discussioncomment-18082533
> >> > > > > > >>> ,
> >> > > > > > >>> > a GitHub Issue
> >> > > > https://github.com/apache/iceberg-rust/issues/3029, and
> >> > > > > > >>> > it's been a long topic of conversation in the past two
> >> weeks in
> >> > > > both
> >> > > > > > >>> the
> >> > > > > > >>> > DataFusion and Iceberg Rust Community Calls to discuss
> >> moving
> >> > > the
> >> > > > > > >>> > DataFusion integration from Iceberg Rust to a separate
> >> > > > repository. I
> >> > > > > > >>> will
> >> > > > > > >>> > try to summarize some of the major points as I
> understand
> >> them,
> >> > > > but the
> >> > > > > > >>> > conversations are the ground truth and please feel free
> to
> >> > > > correct me
> >> > > > > > >>> here.
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > The DataFusion TableProvider integration in Iceberg Rust
> >> makes
> >> > > > > > >>> DataFusion
> >> > > > > > >>> > a dependency for Iceberg Rust. The integration exists
> for
> >> > > > multiple
> >> > > > > > >>> reasons:
> >> > > > > > >>> >
> >> > > > > > >>> > 1) an engine to execute Iceberg Rust's corpus of
> >> sqllogictest
> >> > > > files
> >> > > > > > >>> >
> >> > > > > > >>> > 2) a TableProvider integration for DataFusion users to
> >> interact
> >> > > > with
> >> > > > > > >>> > Iceberg tables
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > Some of the motivations to break out the integration:
> >> > > > > > >>> >
> >> > > > > > >>> > 1) There have been a number of issues and pull requests
> >> against
> >> > > > the
> >> > > > > > >>> > DataFusion TableProvider in Iceberg Rust as users want
> to
> >> add
> >> > > > more
> >> > > > > > >>> > features, and they often go stale. I don't believe there
> >> are
> >> > > many
> >> > > > > > >>> > committers/PMC members familiar with or using the
> >> DataFusion
> >> > > > > > >>> integration.
> >> > > > > > >>> >
> >> > > > > > >>> > 2) Iceberg Rust would like to stay as engine-agnostic as
> >> > > > possible. A
> >> > > > > > >>> > recent DataFusion Ballista integration was declined for
> >> this
> >> > > > reason
> >> > > > > > >>> > https://github.com/apache/iceberg-rust/pull/2613.
> >> > > > > > >>> >
> >> > > > > > >>> > 3) Other projects that rely on both Iceberg Rust and
> >> DataFusion
> >> > > > (e.g.,
> >> > > > > > >>> > Comet) are blocked by Iceberg Rust upgrading its
> >> DataFusion and
> >> > > > Arrow
> >> > > > > > >>> > dependencies before they can upgrade.
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > Some considerations for both communities:
> >> > > > > > >>> >
> >> > > > > > >>> > 1) Where would this DataFusion TableProvider live? Most
> >> > > > specifically,
> >> > > > > > >>> > would it be an Apache-governed project? As folks like
> >> > > @andygrove
> >> > > > point
> >> > > > > > >>> out,
> >> > > > > > >>> > this can affect whether some community members could
> >> contribute
> >> > > > to it.
> >> > > > > > >>> > There is a datafusion-contrib org for DataFusion-related
> >> > > > projects to
> >> > > > > > >>> have
> >> > > > > > >>> > visibility but no Apache governance, but there may be
> >> options
> >> > > to
> >> > > > put it
> >> > > > > > >>> > under an Apache repository.
> >> > > > > > >>> >
> >> > > > > > >>> > 2) How would Iceberg Rust continue to run sqllogictests
> >> for
> >> > > > regression
> >> > > > > > >>> > testing? Does this live in a different repository that
> >> depends
> >> > > > on this
> >> > > > > > >>> new
> >> > > > > > >>> > Iceberg Rust TableProvider crate? Would we be able to
> >> test Pull
> >> > > > > > >>> Requests on
> >> > > > > > >>> > Iceberg Rust with sqllogictests?
> >> > > > > > >>> >
> >> > > > > > >>> > 3) @kevinqliu is familiar with the Python bindings in
> >> Iceberg
> >> > > > Rust,
> >> > > > > > >>> and I
> >> > > > > > >>> > believe that DataFusion dependency might be removed as
> >> well,
> >> > > but
> >> > > > that
> >> > > > > > >>> is
> >> > > > > > >>> > not the core focus of this conversation. He has also
> >> proposed
> >> > > > removing
> >> > > > > > >>> that
> >> > > > > > >>> > and using the DataFusion Python bindings directly.
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > I'm sure I'm forgetting things, but this email is long
> >> enough.
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > Thanks everyone for the discussion thus far, and looking
> >> > > forward
> >> > > > to
> >> > > > > > >>> more
> >> > > > > > >>> > input on this.
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> > -Matt
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>> >
> >> > > > > > >>>
> >> > > > > > >>
> >> > > > > >
> >> > > > >
> >> > > > > Xuanwo
> >> > > > >
> >> > > > > https://xuanwo.io/
> >> > > > >
> >> > > >
> >> > >
> >> >
> >>
> >> ---------------------------------------------------------------------
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> >> For additional commands, e-mail: [email protected]
> >>
> >>
>

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