[python] Add Mosaic row-group stats skipping#8419
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Signed-off-by: QuakeWang <wangfuzheng0814@foxmail.com>
JingsongLi
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Jul 2, 2026
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Purpose
Python Mosaic reads currently apply pushed predicates only after
read_row_group, by filtering the in-memory Arrow batch. This keeps results correct but misses Mosaic row-group statistics pruning.This PR passes the structured Paimon predicate to the Mosaic format reader and evaluates it against Mosaic row-group statistics before reading a row group. The final Arrow predicate filter is still applied after reading, so stats pruning remains an optimization. If stats are missing, conversion fails, or the file schema is older than the table schema, the reader fails open and keeps the previous behavior.
Tests
pytest paimon-python/pypaimon/tests/test_format_mosaic_reader_writer.py -q