risingwave_frontend/optimizer/rule/
limit_push_down_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//
15// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
16// This source code is licensed under both the GPLv2 (found in the
17// COPYING file in the root directory) and Apache 2.0 License
18// (found in the LICENSE.Apache file in the root directory).
19
20use super::{BoxedRule, Rule};
21use crate::optimizer::PlanRef;
22use crate::optimizer::plan_node::{LogicalLimit, LogicalProject, PlanTreeNodeUnary};
23
24pub struct LimitPushDownRule {}
25
26impl Rule for LimitPushDownRule {
27    fn apply(&self, plan: PlanRef) -> Option<PlanRef> {
28        let limit: &LogicalLimit = plan.as_logical_limit()?;
29        let project: LogicalProject = limit.input().as_logical_project()?.to_owned();
30        let input = project.input();
31        let logical_limit = limit.clone_with_input(input);
32        Some(project.clone_with_input(logical_limit.into()).into())
33    }
34}
35
36impl LimitPushDownRule {
37    pub fn create() -> BoxedRule {
38        Box::new(LimitPushDownRule {})
39    }
40}
risingwave_frontend/optimizer/rule/limit_push_down_rule.rs

risingwave_frontend/optimizer/rule/
limit_push_down_rule.rs
