correct parquet leaf index mapping when schema contains struct cols#20698
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adriangb merged 2 commits intoapache:mainfrom Mar 5, 2026
Merged
correct parquet leaf index mapping when schema contains struct cols#20698adriangb merged 2 commits intoapache:mainfrom
adriangb merged 2 commits intoapache:mainfrom
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friendlymatthew
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self review
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| // For primitive-only columns, root indices ARE the leaf indices | ||
| if nested == NestedColumnSupport::PrimitiveOnly { | ||
| return root_indices.to_vec(); | ||
| } |
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Just because a filter only references primitive columns doesn't mean Arrow indices equal Parquet leaf indices.
Struct columns elsewhere in the schema still shift the leaf numbering. The enum encoded the wrong signal (and was only used here), so I removed it and always do the proper mapping
adriangb
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This makes sense to me. Could we add an SLT test?
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Mar 4, 2026
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| // Always map root (Arrow) indices to Parquet leaf indices via the schema | ||
| // descriptor. Arrow root indices only equal Parquet leaf indices when the | ||
| // schema has no group columns (Struct, Map, etc.); when group columns | ||
| // exist, their children become separate leaves and shift all subsequent | ||
| // leaf indices. |
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| // Always map root (Arrow) indices to Parquet leaf indices via the schema | |
| // descriptor. Arrow root indices only equal Parquet leaf indices when the | |
| // schema has no group columns (Struct, Map, etc.); when group columns | |
| // exist, their children become separate leaves and shift all subsequent | |
| // leaf indices. | |
| // Always map root (Arrow) indices to Parquet leaf indices via the schema | |
| // descriptor. Arrow root indices only equal Parquet leaf indices when the | |
| // schema has no group columns (Struct, Map, etc.); when group columns | |
| // exist, their children become separate leaves and shift all subsequent | |
| // leaf indices. | |
| // Struct columns are unsupported. |
adriangb
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Mar 4, 2026
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Which issue does this PR close?
leaf_indices_for_rootsreturns wrong Parquet leaf indices when schema contains Struct columns #20695Rationale for this change
Row filter pushdown assumed Arrow field indices equal Parquet leaf indices, which breaks when Struct columns are present because their children expand into separate leaves and shift all subsequent indices