risingwave_frontend/optimizer/rule/batch/
batch_push_limit_to_scan_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 itertools::Itertools;
21
22use crate::optimizer::PlanRef;
23use crate::optimizer::plan_node::generic::PhysicalPlanRef;
24use crate::optimizer::plan_node::{BatchLimit, BatchSeqScan, PlanTreeNodeUnary};
25use crate::optimizer::rule::{BoxedRule, Rule};
26
27pub struct BatchPushLimitToScanRule {}
28
29impl Rule for BatchPushLimitToScanRule {
30    fn apply(&self, plan: PlanRef) -> Option<PlanRef> {
31        let limit: &BatchLimit = plan.as_batch_limit()?;
32        let limit_input = limit.input();
33        let scan: &BatchSeqScan = limit_input.as_batch_seq_scan()?;
34        if scan.limit().is_some() {
35            return None;
36        }
37        let pushed_limit = limit.limit() + limit.offset();
38        let new_scan = BatchSeqScan::new_with_dist(
39            scan.core().clone(),
40            scan.base.distribution().clone(),
41            scan.scan_ranges().iter().cloned().collect_vec(),
42            Some(pushed_limit),
43        );
44        Some(limit.clone_with_input(new_scan.into()).into())
45    }
46}
47
48impl BatchPushLimitToScanRule {
49    pub fn create() -> BoxedRule {
50        Box::new(BatchPushLimitToScanRule {})
51    }
52}
risingwave_frontend/optimizer/rule/batch/batch_push_limit_to_scan_rule.rs

risingwave_frontend/optimizer/rule/batch/
batch_push_limit_to_scan_rule.rs
