[core] Skip TopN pushdown when a non-partition filter is present#8458
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JingsongLi merged 1 commit intoJul 4, 2026
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applyPushDownTopN pruned splits by sort-column stats without checking a non-partition WHERE filter, which removes rows after pruning, so it could keep too few splits. Match applyPushDownLimit and skip pushdown when one is present.
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Purpose
DataTableBatchScan.applyPushDownTopN prunes splits by the sort column's min/max stats, but a non-partition WHERE filter drops rows at read time, after pruning. A split kept for its stats may have its top rows filtered out, while a split holding the true post-filter top-N may be pruned and never read — so ORDER BY ... LIMIT can return wrong/missing rows.
Skip TopN pushdown when snapshotReader.hasNonPartitionFilter(), mirroring applyPushDownLimit (which already guards both this and the auth filter). Partition-only filters are unaffected, since all surviving rows pass and stats-based pruning stays valid.