risingwave_frontend/optimizer/plan_node/generic/
max_one_row.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::hash::Hash;
16
17use pretty_xmlish::{Str, XmlNode};
18use risingwave_common::catalog::Schema;
19
20use super::{DistillUnit, GenericPlanNode, GenericPlanRef};
21use crate::OptimizerContextRef;
22use crate::optimizer::plan_node::utils::childless_record;
23use crate::optimizer::property::FunctionalDependencySet;
24
25#[derive(Debug, Clone, PartialEq, Eq, Hash)]
26pub struct MaxOneRow<PlanRef> {
27    pub input: PlanRef,
28}
29
30impl<PlanRef: GenericPlanRef> GenericPlanNode for MaxOneRow<PlanRef> {
31    fn ctx(&self) -> OptimizerContextRef {
32        self.input.ctx()
33    }
34
35    fn schema(&self) -> Schema {
36        self.input.schema().clone()
37    }
38
39    fn functional_dependency(&self) -> FunctionalDependencySet {
40        self.input.functional_dependency().clone()
41    }
42
43    fn stream_key(&self) -> Option<Vec<usize>> {
44        self.input.stream_key().map(|s| s.to_vec())
45    }
46}
47
48impl<PlanRef> MaxOneRow<PlanRef> {
49    pub fn new(input: PlanRef) -> Self {
50        MaxOneRow { input }
51    }
52}
53
54impl<PlanRef> DistillUnit for MaxOneRow<PlanRef> {
55    fn distill_with_name<'a>(&self, name: impl Into<Str<'a>>) -> XmlNode<'a> {
56        childless_record(name, vec![])
57    }
58}
risingwave_frontend/optimizer/plan_node/generic/max_one_row.rs

risingwave_frontend/optimizer/plan_node/generic/
max_one_row.rs
