Fix Iceberg read optimization returning NULLs for stats-less manifests#1991
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zvonand wants to merge 1 commit into
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Fix Iceberg read optimization returning NULLs for stats-less manifests#1991zvonand wants to merge 1 commit into
zvonand wants to merge 1 commit into
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When an Iceberg manifest carries no per-column statistics, the parsed `DataFileMetaInfo::columns_info` is empty. The read optimization in `StorageObjectStorageSource::createReader` misread this as "every requested column is absent from the file": it replaced each nullable column with a constant `NULL` and set `need_only_count`, so the reader returned correct row counts but all-NULL values — silent data loss. Gate the absent-column-to-NULL loop on a non-empty `columns_info` so that stats-less manifests fall through to the regular reader, which reads present columns normally and resolves schema-evolution-absent columns via `IcebergMetadata::getInitialSchemaByPath`. Affects `icebergLocal`, `icebergS3`, `icebergAzure`, `icebergHDFS` and their `*Cluster` variants. Antalya-only, introduced by #1069. Add stateless test `04302_iceberg_read_optimization_no_column_stats` with a checked-in stats-less Iceberg fixture and a `generate.py` that reproduces it. C++ change taken from #1895 Closes #1545 Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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C++ change similar to #1895 (without unneeded check)
tests added
Closes #1545
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Fix Iceberg read optimization returning NULL for every column when reading manifests without per-file column statistics (e.g. pyiceberg with default settings). Affects
icebergLocal,icebergS3,icebergAzure,icebergHDFS, and all*Clustervariants.CI/CD Options
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