risingwave_frontend/optimizer/plan_visitor/
execution_mode_decider.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 super::{DefaultBehavior, Merge};
16use crate::PlanRef;
17use crate::optimizer::plan_node::{BatchLimit, BatchSeqScan, BatchValues, PlanTreeNodeUnary};
18use crate::optimizer::plan_visitor::PlanVisitor;
19
20#[derive(Debug, Clone, Default)]
21pub struct ExecutionModeDecider {}
22
23impl ExecutionModeDecider {
24    /// If the plan should run in local mode, return true; otherwise, return false.
25    pub fn run_in_local_mode(plan: PlanRef) -> bool {
26        let mut decider = ExecutionModeDecider {};
27        decider.visit(plan)
28    }
29}
30
31impl PlanVisitor for ExecutionModeDecider {
32    type Result = bool;
33
34    type DefaultBehavior = impl DefaultBehavior<Self::Result>;
35
36    fn default_behavior() -> Self::DefaultBehavior {
37        Merge(|a, b| a & b)
38    }
39
40    /// Point select, index lookup and two side bound range scan.
41    /// select * from t where id = 1
42    /// select * from t where k = 1
43    /// select * from t where id between 1 and 5
44    fn visit_batch_seq_scan(&mut self, batch_seq_scan: &BatchSeqScan) -> bool {
45        !batch_seq_scan.scan_ranges().is_empty()
46            && batch_seq_scan
47                .scan_ranges()
48                .iter()
49                .all(|x| x.has_eq_conds() || x.two_side_bound())
50    }
51
52    /// Simple value select.
53    /// select 1
54    fn visit_batch_values(&mut self, _batch_values: &BatchValues) -> bool {
55        true
56    }
57
58    /// Limit scan.
59    /// select * from t limit 1
60    /// select * from t order by k limit 1
61    fn visit_batch_limit(&mut self, batch_limit: &BatchLimit) -> bool {
62        if let Some(batch_seq_scan) = batch_limit.input().as_batch_seq_scan()
63            && batch_seq_scan.scan_ranges().is_empty()
64            && batch_limit.limit() + batch_limit.offset() < 100
65        {
66            true
67        } else {
68            self.visit(batch_limit.input())
69        }
70    }
71}
risingwave_frontend/optimizer/plan_visitor/execution_mode_decider.rs

risingwave_frontend/optimizer/plan_visitor/
execution_mode_decider.rs
