[spark] Support merge schema in MERGE INTO#7789
Open
Zouxxyy wants to merge 2 commits intoapache:masterfrom
Open
[spark] Support merge schema in MERGE INTO#7789Zouxxyy wants to merge 2 commits intoapache:masterfrom
Zouxxyy wants to merge 2 commits intoapache:masterfrom
Conversation
JingsongLi
reviewed
May 9, 2026
| } | ||
|
|
||
| /** Reorder source struct fields to match target field order by name, recursing into nested types. */ | ||
| private def reorderStructByName( |
Contributor
There was a problem hiding this comment.
reorderStructByName crashes when target struct has fields absent from source
Should we support this?
The same issue applies to MapType value reordering in reorderFieldsByName.
JingsongLi
reviewed
May 9, 2026
| * reorder and fill nulls for missing sub-fields. | ||
| */ | ||
| private def alignColumns( | ||
| def alignColumns( |
Contributor
There was a problem hiding this comment.
SchemaHelper.scala now handles ArrayType alignment via transform, but MapType is not handled. Meanwhile, AssignmentAlignmentHelper.reorderFieldsByName does handle MapType. This inconsistency means the DataFrame write path won't align map values while the MERGE path will.
Is this a problem?
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Purpose
Add schema evolution support for MERGE INTO and fix nested-field alignment.
spark.paimon.write.merge-schema=true,UPDATE */INSERT *evolves target schema with new source columns. Star clauses pull from source by name; explicit clauses fill NULL.FROM_STARTreeNodeTagpreserves the original star intent, so a fully-listed explicit clause is not mistaken for*.AssignmentAlignmentHelpernow reorders nested struct / array / map fields by name.Scope
UPDATE */INSERT *→ evolveTests
13 new cases in
MergeIntoTableTestBaseplusWHEN NOT MATCHED BY SOURCEcoverage inMergeIntoNotMatchedBySourceTest.