risingwave_frontend/optimizer/rule/
over_window_split_rule.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::collections::HashMap;
16
17use itertools::Itertools;
18
19use super::{BoxedRule, Rule};
20use crate::PlanRef;
21
22pub struct OverWindowSplitRule;
23
24impl OverWindowSplitRule {
25    pub fn create() -> BoxedRule {
26        Box::new(OverWindowSplitRule)
27    }
28}
29
30impl Rule for OverWindowSplitRule {
31    fn apply(&self, plan: PlanRef) -> Option<PlanRef> {
32        let over_window = plan.as_logical_over_window()?;
33        let mut rank_func_seq = 0;
34        let groups: HashMap<_, _> = over_window
35            .window_functions()
36            .iter()
37            .enumerate()
38            .map(|(idx, func)| {
39                let func_seq = if func.kind.is_numbering() {
40                    rank_func_seq += 1;
41                    rank_func_seq
42                } else {
43                    0
44                };
45                ((&func.order_by, &func.partition_by, func_seq), idx)
46            })
47            .into_group_map();
48        Some(over_window.split_with_rule(groups.into_values().sorted().collect()))
49    }
50}
risingwave_frontend/optimizer/rule/over_window_split_rule.rs

risingwave_frontend/optimizer/rule/
over_window_split_rule.rs
