[Spark][Prototype] Schema evolution in DSv2 INSERT#6140
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johanl-db wants to merge 1 commit intodelta-io:masterfrom
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[Spark][Prototype] Schema evolution in DSv2 INSERT#6140johanl-db wants to merge 1 commit intodelta-io:masterfrom
johanl-db wants to merge 1 commit intodelta-io:masterfrom
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aokolnychyi
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Mar 16, 2026
…ion, OverwritePartitionsDynamic ### What changes were proposed in this pull request? Adds support for schema evolution during INSERT operations (AppendData, OverwriteByExpression, OverwritePartitionsDynamic) When the table reports capability `AUTOMATIC_SCHEMA_EVOLUTION`, a new analyzer rule `ResolveInsertSchemaEvolution` collects new columns and nested fields present in the source query but not in the table schema, and adds them to the target table by calling `catalog.alterTable()` Identifying new columns/fields respects the resolution semantics of INSERT operations: matching fields by-name vs by-position. This builds on previous from szehon-ho , in particular #51698. The first two commits move this previous code around to reuse it, the core of the implementation is in the [third commit](7be9d2a). ### Why are the changes needed? The `WITH SCHEMA EVOLUTION` syntax for SQL inserts was added recently: #53732. This actually implements schema evolution behind this syntax. ### Does this PR introduce _any_ user-facing change? Yes, when the `WITH SCHEMA EVOLUTION` clause is specified in SQL INSERT operations, new columns and nested fields in the source data will be added to the target table - assuming the data source supports schema evolution (capability AUTOMATIC_SCHEMA_EVOLUTION): ``` CREATE TABLE target (id INT); INSERT INTO target VALUES (1); INSERT WITH SCHEMA EVOLUTION INTO target SELECT 2 AS id, "two" AS value; SELECT * FROM target; | id | value | |----|-------| | 1 | null | | 2 | "two" | ``` ### How was this patch tested? Added basic testing in `DataSourceV2SQLSuite`. Integrated with Delta and ran extensive Delta test harness for schema evolution against this implementation. See delta-io/delta#6140. A number of expected failures for tests that would need to be updated on Delta side (different error class returned, negative tests checking something specifically doesn't work if a fix is disabled, ..) Closes #54488 from johanl-db/dsv2-schema-evolution-insert. Authored-by: Johan Lasperas <[email protected]> Signed-off-by: Anton Okolnychyi <[email protected]>
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Description
This requires apache/spark#54488 in Spark
Demonstrate using Spark DSv2 code path to handle schema evolution for INSERT operations instead of Delta.
That is: rely on the new rule
ResolveInsertSchemaEvolutionintroduced in the linked Spark PR instead ofDeltaAnalysisNote: this actually goes one step further and includes changes for type evolution (see
SupportsTypeEvolution), which I haven't pushed to Spark yet, so it won't build unlessSupportsTypeEvolution/canChangeTypeare removedHow was this patch tested?
Building locally together with apache/spark#54488 and running tests.
After triaging them, all failures are somewhat expected - e.g. negative tests covering incorrect null struct expansion if the corresponding is disabled, or different error class returned.