risingwave_frontend/optimizer/rule/stream/
generate_series_with_now_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
15use risingwave_common::types::DataType;
16use risingwave_pb::expr::table_function::PbType as PbTableFuncType;
17
18use crate::expr::{Expr, ExprRewriter};
19use crate::optimizer::plan_node::{LogicalNow, generic};
20use crate::optimizer::rule::prelude::{PlanRef, *};
21
22pub struct GenerateSeriesWithNowRule {}
23impl Rule<Logical> for GenerateSeriesWithNowRule {
24    fn apply(&self, plan: PlanRef) -> Option<PlanRef> {
25        let ctx = plan.ctx();
26        let table_func = plan.as_logical_table_function()?.table_function();
27
28        if !table_func.args.iter().any(|arg| arg.has_now()) {
29            return None;
30        }
31
32        if !(table_func.function_type == PbTableFuncType::GenerateSeries
33            && table_func.args.len() == 3
34            && table_func.args[0].return_type() == DataType::Timestamptz
35            && table_func.args[1].is_now()
36            && table_func.args[2].return_type() == DataType::Interval)
37        {
38            // only convert `generate_series(const timestamptz, now(), const interval)`
39            ctx.warn_to_user(
40                "`now()` is currently only supported in `generate_series(timestamptz, timestamptz, interval)` function as `stop`. \
41                You may not using it correctly. Please kindly check the document."
42            );
43            return None;
44        }
45
46        let start_timestamp = ctx
47            .session_timezone()
48            .rewrite_expr(table_func.args[0].clone())
49            .try_fold_const()
50            .transpose()
51            .ok()
52            .flatten()
53            .flatten();
54        let interval = ctx
55            .session_timezone()
56            .rewrite_expr(table_func.args[2].clone())
57            .try_fold_const()
58            .transpose()
59            .ok()
60            .flatten()
61            .flatten();
62
63        if start_timestamp.is_none() || interval.is_none() {
64            ctx.warn_to_user(
65                "When using `generate_series` with `now()`, the `start` and `step` must be non-NULL constants",
66            );
67            return None;
68        }
69
70        Some(
71            LogicalNow::new(generic::Now::generate_series(
72                ctx,
73                start_timestamp.unwrap().into_timestamptz(),
74                interval.unwrap().into_interval(),
75            ))
76            .into(),
77        )
78    }
79}
80
81impl GenerateSeriesWithNowRule {
82    pub fn create() -> BoxedRule {
83        Box::new(Self {})
84    }
85}
risingwave_frontend/optimizer/rule/stream/generate_series_with_now_rule.rs

risingwave_frontend/optimizer/rule/stream/
generate_series_with_now_rule.rs
