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

risingwave_frontend/optimizer/rule/batch/
batch_push_limit_to_scan_rule.rs
