Release DataFusion `55.1.0` (minor/patch) Release (Sep 2026)

[alamb]

Is your feature request related to a problem or challenge?

• Part of [EPIC] DataFusion Releases #19783
• Follow on to Release DataFusion 55.0.0 (Jul / Aug 2026) #22393

Plan a 55.0.1 or 55.1.0 patch release to fix any bugs / issues found in 55.0.0.

Steps:

• Update version and changelog
• Test with DataFusion Python
• Test with DataFusion Comet
• Test with delta.rs:
• Test vortex:
• Test with iceberg-rust:
• Test with LakeSail:
• Test with parquet viewer
• Test with datafusion-materialized-views
• Voting Thread:
• Publish to crates.io

Potential Content:

Bug Fixes

• fix: preserve MERGE target qualifier bindings #24429 (@wirybeaver) -- breaking API change, so can't include it
• Issue Parquet filter pushdown silently drops a get_field predicate when the file needs schema adaptation (wrong results) #24109 (@adriangb); Backport: [branch-55] fix: apply struct field filters when the file schema needs adaptation (#24125) #24530
• Issue GroupedHashAggregateStream::emit throws ArrowError: column types must match schema types #24069 (@hsiang-c); Backport: [branch-55] fix: adapt input batches with stricter nested nullability to planned schema in aggregation (#24394) #24699
• Issue UnnestExec ignores datafusion.execution.batch_size #24383 (@andygrove); Backport: [branch-55] fix: make UnnestExec respect datafusion.execution.batch_size (#24384) #24529
• Issue fix(ffi): use the session's LogicalExtensionCodec in create_physical_plan #24690 (@timsaucer); Backport: [branch-55] fix(ffi): use the session's LogicalExtensionCodec in create_physical_plan (#24690) #24694
• Issue Projection field metadata is lost during physical plan optimization #24721 (@gene-bordegaray); Backport: TODO
• Issue Physical-plan serialization drops ProjectionExec metadata #24695 (@gene-bordegaray) Not a regression from 54 and will require breaking API change
• Issue DF 55: physical-optimizer enforce_sorting panics on RightMark joins #24717 (@Tpt); Backport:[branch-55] Fix panic on RightMark hash joins when propagating ordering (#24718) #24759
• Issue FFI constructors silently discard arguments when the input is already foreign #24722 (@timsaucer) Backport: [branch-55] fix: preserve provided arguments during FFI object construction (#24723) #24752
• [branch-55] Align metadata propagation through Physical and Logical casts (#23169) #24875 dependency for Projection field metadata is lost during physical plan optimization #24721
• Issue panic: 'StructArray::new' on zero-field (empty) structs in ScalarValue::compact and ScalarValue::new_default #24581 (@unikdahal); Backport: [branch-55] fix(common): support empty struct in ScalarValue::compact and new_default (#24582) #24876

Performance

• TBD

Other

• TBD

Minor Features:

• feat: add basic MemTable MERGE INTO support #24195 (@wirybeaver) -- same API changes as fix: preserve MERGE target qualifier bindings #24429

[alamb]

Is there anyone waiting on this release ?

Is there any PMC member to help run it?

[timsaucer]

I added an issue (#24688) and fix (#24690) that datafusion-python will need before we release 55.0.0. I can run this release since I'm the one interested in getting it.

[alamb]

Thanks ! Just let me know what I can do to help

[timsaucer]

I mentioned on the PR but I think #24429 may not be eligible for back port. #24195 looks like it has the same issue (or was built on top of #24429). Other than that I've put up two PRs that are cherry picks targeting branch-55 linked above

• [branch-55] fix(ffi): use the session's LogicalExtensionCodec in create_physical_plan (#24690) #24694
• [branch-55] fix: adapt input batches with stricter nested nullability to planned schema in aggregation (#24394) #24699