[fix](parquet) Fill columns absent from the physical parquet schema - #66850
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[fix](parquet) Fill columns absent from the physical parquet schema#66850liutang123 wants to merge 1 commit into
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A table-format reader builds its schema-change tree from FE-supplied schema info (history_schema_info, field-id mapping), so it can map a table column to a file column that is not present in this file's physical parquet schema — for example a column added by schema change whose default was never materialized into the older data files. Such a column was neither read nor filled: _init_read_columns walks the file schema in physical order, so the column was silently dropped, and because children_column_exists() reported it as present it was never classified as fill-missing either. It then surfaced downstream as a 0-row column, tripping the filter.size() == offsets.size() check in filter_block_internal. Detect this case in _do_init_reader by checking the mapped file column against the physical schema, and demote the column to a missing column so it is filled with its default/null values.
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run buildall |
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TPC-H: Total hot run time: 16851 ms |
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TPC-DS: Total hot run time: 80393 ms |
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TPC-DS: Total hot run time: 81181 ms |
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BE UT Coverage ReportIncrement line coverage Increment coverage report
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What problem does this PR solve?
A table-format reader builds its schema-change tree from FE-supplied schema info (history_schema_info, field-id mapping), so it can map a table column to a file column that is not present in this file's physical parquet schema — for example a column added by schema change whose default was never materialized into the older data files.
Such a column was neither read nor filled: _init_read_columns walks the file schema in physical order, so the column was silently dropped, and because children_column_exists() reported it as present it was never classified as fill-missing either. It then surfaced downstream as a 0-row column, tripping the filter.size() == offsets.size() check in filter_block_internal.
Detect this case in _do_init_reader by checking the mapped file column against the physical schema, and demote the column to a missing column so it is filled with its default/null values.
Stack:
Issue Number: close #xxx
Related PR: #xxx
Problem Summary:
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