risingwave_frontend/optimizer/plan_node/generic/
union.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 pretty_xmlish::{Pretty, StrAssocArr};
16use risingwave_common::catalog::Schema;
17
18use super::{GenericPlanNode, GenericPlanRef, impl_distill_unit_from_fields};
19use crate::optimizer::optimizer_context::OptimizerContextRef;
20use crate::optimizer::property::FunctionalDependencySet;
21
22/// `Union` returns the union of the rows of its inputs.
23/// If `all` is false, it needs to eliminate duplicates.
24#[derive(Debug, Clone, PartialEq, Eq, Hash)]
25pub struct Union<PlanRef> {
26    pub all: bool,
27    pub inputs: Vec<PlanRef>,
28    /// It is used by streaming processing. We need to use `source_col` to identify the record came
29    /// from which source input.
30    /// We add it as a logical property, because we need to derive the logical pk based on it.
31    pub source_col: Option<usize>,
32}
33
34impl<PlanRef: GenericPlanRef> GenericPlanNode for Union<PlanRef> {
35    fn schema(&self) -> Schema {
36        let mut schema = self.inputs[0].schema().clone();
37        if let Some(source_col) = self.source_col {
38            schema.fields[source_col].name = "$src".to_owned();
39            schema
40        } else {
41            schema
42        }
43    }
44
45    fn stream_key(&self) -> Option<Vec<usize>> {
46        // Union all its inputs pks + source_col if exists
47        let mut pk_indices = vec![];
48        for input in &self.inputs {
49            for pk in input.stream_key()? {
50                if !pk_indices.contains(pk) {
51                    pk_indices.push(*pk);
52                }
53            }
54        }
55        if let Some(source_col) = self.source_col {
56            pk_indices.push(source_col)
57        }
58        Some(pk_indices)
59    }
60
61    fn ctx(&self) -> OptimizerContextRef {
62        self.inputs[0].ctx()
63    }
64
65    fn functional_dependency(&self) -> FunctionalDependencySet {
66        FunctionalDependencySet::new(self.inputs[0].schema().len())
67    }
68}
69
70impl<PlanRef: GenericPlanRef> Union<PlanRef> {
71    pub fn fields_pretty<'a>(&self) -> StrAssocArr<'a> {
72        vec![("all", Pretty::debug(&self.all))]
73    }
74}
75impl_distill_unit_from_fields!(Union, GenericPlanRef);
risingwave_frontend/optimizer/plan_node/generic/union.rs

risingwave_frontend/optimizer/plan_node/generic/
union.rs
