fix: normalize nested field names in RecordBatchTransformer#2251
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vovacf201 wants to merge 1 commit intoapache:mainfrom
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fix: normalize nested field names in RecordBatchTransformer#2251vovacf201 wants to merge 1 commit intoapache:mainfrom
vovacf201 wants to merge 1 commit intoapache:mainfrom
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* fix: normalize nested field names in RecordBatchTransformer
Parquet files use "item" as the List inner field name (Parquet spec)
while Iceberg uses "element" (Iceberg spec). Similarly, Parquet uses
"entries" for Map inner fields while Iceberg uses "key_value".
The RecordBatchTransformer previously used equals_datatype() (which
ignores field names) to decide between PassThrough and Promote. This
meant columns with mismatched nested field names were passed through
unchanged, causing downstream consumers that use strict schema
validation (like DataFusion's concat_batches) to fail with:
"column types must match schema types, expected List(Field { name:
element ..."
Fix: use a 3-way comparison in generate_transform_operations:
1. Strict == match → PassThrough (no cast needed)
2. equals_datatype() but != (field names differ) → Promote (cast to
normalize names)
3. Neither → Promote (actual type promotion)
* style: apply nightly rustfmt formatting
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Parquet files use "item" as the List inner field name (Parquet spec) while Iceberg uses "element" (Iceberg spec). Similarly, Parquet uses "entries" for Map inner fields while Iceberg uses "key_value".
The RecordBatchTransformer previously used
equals_datatype()(which ignores field names) to decide between PassThrough and Promote. This meant columns with mismatched nested field names were passed through unchanged, causing downstream consumers that use strict schema validation (like DataFusion'sconcat_batches) to fail with:"column types must match schema types, expected List(Field { name: element ..."
Fix: use a 3-way comparison in
generate_transform_operations:==match -> PassThrough (no cast needed)equals_datatype()but!=(field names differ) -> Promote (cast to normalize names)Cherry-picked from risingwavelabs/iceberg-rust commit 2e56dde