[ES-1804970] Fix CloudFetch returning stale column names from cached results#346
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…results When the server result cache serves Arrow IPC files from a prior query, the embedded schema contains stale column aliases. The Go driver's CloudFetch path read these stale names directly, while the local path already used the authoritative schema from GetResultSetMetadata. Pass the authoritative schema bytes into NewCloudBatchIterator and replace stale column names on deserialized records using array.NewRecord, which is zero-copy (shares underlying column data). Co-authored-by: Isaac Signed-off-by: Sreekanth Vadigi <sreekanth.vadigi@databricks.com>
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Signed-off-by: Sreekanth Vadigi <sreekanth.vadigi@databricks.com>
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Summary
Fixes a bug where
arrow.Record.Schema()returns stale column aliases when CloudFetch serves cached Arrow IPC files from a structurally identical prior query with differentASaliases.NewCloudBatchIteratorwas not receiving the authoritative schema bytes fromGetResultSetMetadata, unlike the local batch path which already had this. CloudFetch Arrow IPC files have column names baked in from the original query, and the driver was reading them as-is.arrowSchemaBytes(the authoritative schema fromGetResultSetMetadata) intoNewCloudBatchIterator. After records are deserialized from the IPC stream, replace the stale schema with the authoritative one usingarray.NewRecord()(zero-copy — shares underlying column data, only swaps metadata).Changes
arrowRecordIterator.go— Passri.arrowSchemaBytestoNewCloudBatchIteratorinnewBatchIterator()arrowRows.go— PassschemaBytestoNewCloudBatchIteratorinNewArrowRowScanner()batchloader.go— Core fix:NewCloudBatchIteratoracceptsarrowSchemaBytes, parses into*arrow.Schema, stores onbatchIteratorbatchIterator.Next()applies override schema to CloudFetch records only (local path is untouched,overrideSchemaisnil)schemaFromIPCBytes()helperWarnlevelbatchloader_test.go— AddedTestCloudFetchSchemaOverridewith two subtests:["id","name"]are overridden to["x","y"]nilschema bytes pass through original names unchangedWho is affected
Go driver users with CloudFetch enabled (
WithCloudFetch(true)) who readarrow.Record.Schema()directly. Python, ODBC, and JDBC drivers are not affected.Test plan
internal/rows/arrowbased/)TestCloudFetchSchemaOverridecovers the override and no-override pathssamples.tpch.lineitem(~30M rows) with two queries differing only in column aliases — confirmedarrow.Record.Schema()now returns correct aliasesThis pull request was AI-assisted by Isaac.