kumarUjjawal opened a new pull request, #22118:
URL: https://github.com/apache/datafusion/pull/22118
## Which issue does this PR close?
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- Closes #8342.
## Rationale for this change
Parquet min/max statistics are only safe to use when DataFusion knows the
order used to write them. If DataFusion uses stats with the wrong order, it can
skip data that should be read and return wrong results.
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Why are you proposing this change? If this is already explained clearly in
the issue then this section is not needed.
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## What changes are included in this PR?
This PR checks Parquet column order before using min/max statistics for
file, row group, and page pruning.
It also skips unsafe deprecated min/max statistics for columns whose natural
order is not signed.
For files without column order metadata, DataFusion now uses a conservative
fallback. It only uses min/max pruning for signed-order columns.
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## Are these changes tested?
Yes
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## Are there any user-facing changes?
Yes.
Queries over older or external Parquet files without column order metadata
may scan more data for unsigned integers, strings, binary values, and booleans.
This is intentional to avoid wrong results.
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