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[SPARK-55690] Schema evolution in DSv2 AppendData, OverwriteByExpression, OverwritePartitionsDynamic #54488

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[SPARK-55690] Schema evolution in DSv2 AppendData, OverwriteByExpression, OverwritePartitionsDynamic #54488

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b3963d0
Move ResolveMergeIntoSchemaEvolution.scala -> ResolveMergeIntoSchemaE…
johanl-db Feb 25, 2026
05b32cb
Move schemaChanges from MergeIntoTable to ResolveSchemaEvolution
johanl-db Feb 25, 2026
7be9d2a
Schema evolution for DSv2 INSERT
johanl-db Feb 25, 2026
6bc2956
Merge branch 'master' into dsv2-schema-evolution-insert
johanl-db Feb 25, 2026
a3042e3
Add tests, address comments
johanl-db Feb 26, 2026
aeae2b4
Add tests
johanl-db Feb 27, 2026
862fdb6
Fix checking catalog name in test
johanl-db Mar 3, 2026
42ca213
Refactor to use single schema evolution rule + address comments
johanl-db Mar 10, 2026
18f10a1
Minor improvements
johanl-db Mar 10, 2026
b7e303f
Merge remote-tracking branch 'spark/master' into dsv2-schema-evolutio…
johanl-db Mar 11, 2026
0cc771f
Resolve conflicts from https://github.com/apache/spark/pull/54704
johanl-db Mar 11, 2026
65ba49a
Address comments
johanl-db Mar 13, 2026
ac8fca6
Merge remote-tracking branch 'spark/master' into dsv2-schema-evolutio…
johanl-db Mar 13, 2026
56ea329
Fix val->def writePrivileges override
johanl-db Mar 13, 2026
d777acc
Update tests, remove mergeSchema in REPLACE WHERE
johanl-db Mar 14, 2026
f8374b6
Address nits
johanl-db Mar 16, 2026
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22 changes: 15 additions & 7 deletions sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -450,6 +450,7 @@ class Analyzer(
DeduplicateRelations ::
ResolveCollationName ::
ResolveMergeIntoSchemaEvolution ::
ResolveInsertSchemaEvolution ::
ValidateEventTimeWatermarkColumn ::
new ResolveReferences(catalogManager) ::
// Please do not insert any other rules in between. See the TODO comments in rule
Expand Down Expand Up @@ -1178,38 +1179,44 @@ class Analyzer(
AppendData.byName(
r,
query,
writeOptions = schemaEvolutionWriteOption)
writeOptions = schemaEvolutionWriteOption,
withSchemaEvolution = i.withSchemaEvolution)
} else {
AppendData.byPosition(
r,
query,
writeOptions = schemaEvolutionWriteOption)
writeOptions = schemaEvolutionWriteOption,
withSchemaEvolution = i.withSchemaEvolution)
}
} else if (conf.partitionOverwriteMode == PartitionOverwriteMode.DYNAMIC) {
if (isByName) {
OverwritePartitionsDynamic.byName(
r,
query,
writeOptions = schemaEvolutionWriteOption)
writeOptions = schemaEvolutionWriteOption,
withSchemaEvolution = i.withSchemaEvolution)
} else {
OverwritePartitionsDynamic.byPosition(
r,
query,
writeOptions = schemaEvolutionWriteOption)
writeOptions = schemaEvolutionWriteOption,
withSchemaEvolution = i.withSchemaEvolution)
}
} else {
if (isByName) {
OverwriteByExpression.byName(
table = r,
df = query,
deleteExpr = staticDeleteExpression(r, staticPartitions),
writeOptions = schemaEvolutionWriteOption)
writeOptions = schemaEvolutionWriteOption,
withSchemaEvolution = i.withSchemaEvolution)
} else {
OverwriteByExpression.byPosition(
table = r,
query = query,
deleteExpr = staticDeleteExpression(r, staticPartitions),
writeOptions = schemaEvolutionWriteOption)
writeOptions = schemaEvolutionWriteOption,
withSchemaEvolution = i.withSchemaEvolution)
}
}
}
Expand Down Expand Up @@ -3594,7 +3601,8 @@ class Analyzer(
override def apply(plan: LogicalPlan): LogicalPlan = plan.resolveOperatorsWithPruning(
_.containsPattern(COMMAND), ruleId) {
case v2Write: V2WriteCommand
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@aokolnychyi aokolnychyi Mar 12, 2026

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@johanl-db @szehon-ho, can you folks explain the relation between skipSchemaEvolution via ACCEPT_ANY_SCHEMA and automatic schema evolution via AUTOMATIC_SCHEMA_EVOLUTION? Are these two mutually exclusive? Or can they co-exist? MERGE vs INSERT?

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@szehon-ho szehon-ho Mar 12, 2026

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Merge with ACCEPT_ANY_SCHEMA on normal DSV2 data source breaks today as it relies on external rule to resolve the merge.

I think insert already works with ACCEPT_ANY_SCHEMA, and this would be another mode. Probably should be mutually exclusive?

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@johanl-db johanl-db Mar 13, 2026

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Discussed with @aokolnychyi this morning: AUTOMATIC_SCHEMA_EVOLUTION and ACCEPT_ANY_SCHEMA are not exclusive:

  • AUTOMATIC_SCHEMA_EVOLUTION allows the rule ResolveSchemaEvolution to trigger
  • ACCEPT_ANY_SCHEMA skips some resolution steps in Spark, under the assumption that the connector will handle them. In particular:
    • For INSERT, skips schema alignment in ResolveOutputRelation
    • For MERGE: skips clause resolution in Analyzer, and skips schema alignment in ResolveRowLevelCommandAssignments

At least, that's how Spark applies these capabilities today, even though the name ACCEPT_ANY_SCHEMA suggests more.

The connector can choose to set either depending on the resolution flow that suits.
For example, Delta today always handles schema evolution itself (doesn't set AUTOMATIC_SCHEMA_EVOLUTION) and does resolution / schema alignment (sets ACCEPT_ANY_SCHEMA)

As Delta moves to DSv2, my plan is to have two phases:

  1. Delta sets both AUTOMATIC_SCHEMA_EVOLUTION and ACCEPT_ANY_SCHEMA: Spark handles schema evolution, but Delta takes over to do the resolution of MERGE clauses initially, and then do schema alignment for both INSERT and MERGE
  2. Delta sets only AUTOMATIC_SCHEMA_EVOLUTION: once we've reconciled all behavior differences between how Delta and Spark do schema alignment today, we hand over schema alignment to Spark. This will require substantial efforts, and careful breaking changes (if at all possible) in Delta

if v2Write.table.resolved && v2Write.query.resolved && !v2Write.outputResolved =>
if v2Write.table.resolved && v2Write.query.resolved && !v2Write.outputResolved &&
!v2Write.needSchemaEvolution =>
validateStoreAssignmentPolicy()
TableOutputResolver.suitableForByNameCheck(v2Write.isByName,
expected = v2Write.table.output, queryOutput = v2Write.query.output)
Expand Down
85 changes: 0 additions & 85 deletions ...c/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveMergeIntoSchemaEvolution.scala
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