2010YOUY01 commented on code in PR #22899: URL: https://github.com/apache/datafusion/pull/22899#discussion_r3396528767
########## datafusion/physical-plan/src/aggregates/utils.rs: ########## @@ -0,0 +1,115 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use arrow::record_batch::RecordBatch; + +use crate::metrics; + +/// Tracks if the aggregate should skip partial aggregations +/// +/// See "partial aggregation" discussion on +/// [`crate::aggregates::row_hash::GroupedHashAggregateStream`]. +pub(super) struct SkipAggregationProbe { + // ======================================================================== + // PROPERTIES: + // These fields are initialized at the start and remain constant throughout + // the execution. + // ======================================================================== + /// Aggregation ratio check performed when the number of input rows exceeds + /// this threshold (from `SessionConfig`) + probe_rows_threshold: usize, + /// Maximum ratio of `num_groups` to `input_rows` for continuing aggregation + /// (from `SessionConfig`). If the ratio exceeds this value, aggregation + /// is skipped and input rows are directly converted to output + probe_ratio_threshold: f64, + + // ======================================================================== + // STATES: + // Fields changes during execution. Can be buffer, or state flags that + // influence the execution in parent `GroupedHashAggregateStream` + // ======================================================================== + /// Number of processed input rows (updated during probing) + input_rows: usize, + /// Number of total group values for `input_rows` (updated during probing) + num_groups: usize, + + /// Flag indicating further data aggregation may be skipped (decision made + /// when probing complete) + should_skip: bool, + /// Flag indicating further updates of `SkipAggregationProbe` state won't + /// make any effect (set either while probing or on probing completion) + is_locked: bool, + + // ======================================================================== + // METRICS: + // ======================================================================== + /// Number of rows where state was output without aggregation. + /// + /// * If 0, all input rows were aggregated (should_skip was always false) + /// + /// * if greater than zero, the number of rows which were output directly + /// without aggregation + skipped_aggregation_rows: metrics::Count, +} + +impl SkipAggregationProbe { + pub(super) fn new( + probe_rows_threshold: usize, + probe_ratio_threshold: f64, + skipped_aggregation_rows: metrics::Count, + ) -> Self { + Self { + input_rows: 0, + num_groups: 0, + probe_rows_threshold, + probe_ratio_threshold, + should_skip: false, + is_locked: false, + skipped_aggregation_rows, + } + } + + /// Updates `SkipAggregationProbe` state: + /// - increments the number of input rows + /// - replaces the number of groups with the new value + /// - on `probe_rows_threshold` exceeded calculates + /// aggregation ratio and sets `should_skip` flag + /// - if `should_skip` is set, locks further state updates + pub(super) fn update_state(&mut self, input_rows: usize, num_groups: usize) { + if self.is_locked { + return; + } + self.input_rows += input_rows; + self.num_groups = num_groups; + if self.input_rows >= self.probe_rows_threshold { + self.should_skip = self.num_groups as f64 / self.input_rows as f64 + > self.probe_ratio_threshold; + // Set is_locked to true only if we have decided to skip, otherwise we can try to skip + // during processing the next record_batch. + self.is_locked = self.should_skip; + } + } + + pub(super) fn should_skip(&self) -> bool { + self.should_skip + } + + /// Record the number of rows that were output directly without aggregation + pub(super) fn record_skipped(&mut self, batch: &RecordBatch) { + self.skipped_aggregation_rows.add(batch.num_rows()); + } +} Review Comment: Good point, moved in [f0b2d79](https://github.com/apache/datafusion/pull/22899/commits/f0b2d79c4dd0095f89bd75927c79dc650019a900) ########## datafusion/physical-plan/src/aggregates/mod.rs: ########## @@ -4161,6 +4103,102 @@ mod tests { Ok(()) } Review Comment: [f0b2d79](https://github.com/apache/datafusion/pull/22899/commits/f0b2d79c4dd0095f89bd75927c79dc650019a900) -- This is an automated message from the Apache Git Service. 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