gabotechs opened a new issue, #25622: URL: https://github.com/apache/datafusion/issues/25622
## Describe the bug Filtering a window ranking to the first ten rows retains the full input estimate. The reduced example estimates 73,049 rows and emits ten; the window input itself is estimated correctly. ## To Reproduce From the repository root, with [PR #25570](https://github.com/apache/datafusion/pull/25570) applied: ```sh cargo build --profile ci --locked -p datafusion-benchmarks --bin dfbench repro_dir=$(mktemp -d) mkdir -p "$repro_dir/data" curl --fail --location \ https://raw.githubusercontent.com/apache/datafusion-benchmarks/32f67477f692453616d2fa98a05a37c5eb4cae49/tpcds/data/sf1/date_dim.parquet \ -o "$repro_dir/data/date_dim.parquet" cat > "$repro_dir/repro.sql" <<'SQL' SET datafusion.execution.target_partitions = 1; SET datafusion.optimizer.enable_dynamic_filter_pushdown = false; SELECT * FROM ( SELECT d_date_sk, ROW_NUMBER() OVER (ORDER BY d_date_sk) AS rn FROM date_dim ) t WHERE rn <= 10; SELECT * FROM ( SELECT d_date_sk, RANK() OVER (ORDER BY d_date_sk) AS rn FROM date_dim ) t WHERE rn <= 10; SQL target/ci/dfbench statistics \ --path "$repro_dir/data" --query_path "$repro_dir/repro.sql" ``` Observed at [this revision](https://github.com/apache/datafusion/commit/6c320561b5b1aef7a235a12435c3c96b62956c67) with the pinned SF1 data above. Inspect the SELECT reports in order; ignore the empty SET reports. | Predicate | FilterExec node | Estimated rows | Actual rows | | ------------------ | --------------- | -------------: | ----------: | | ROW_NUMBER() <= 10 | `0.0` | 73,049 | 10 | | RANK() <= 10 | `0.0` | 73,049 | 10 | ## Expected behavior Expose usable ranking-column statistics. A global ROW_NUMBER() <= 10 has an upper bound of ten rows. RANK needs tie-aware estimation, and partitioned windows need partition-count estimates; neither can generally use that same global bound. ## Additional context Reduced from the ranking filters in TPC-DS Q49/Q67/Q70, with ROW_NUMBER added as a stronger semantic control. BoundedWindowAggExec currently appends unknown column statistics for its window outputs. This concerns estimates, independently of whether execution can stop early. Part of #25610. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
