risingwave_frontend/catalog/system_catalog/pg_catalog/
pg_settings.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::system_param::reader::SystemParamsRead;
16use risingwave_common::types::{DataType, Datum, Fields, ToOwnedDatum, WithDataType};
17use risingwave_frontend_macro::system_catalog;
18
19use crate::catalog::system_catalog::SysCatalogReaderImpl;
20
21/// The catalog `pg_settings` stores settings.
22/// Ref: [`https://www.postgresql.org/docs/current/view-pg-settings.html`]
23#[derive(Fields)]
24#[primary_key(name, context)]
25struct PgSetting {
26    name: String,
27    setting: String,
28    short_desc: String,
29    context: Context,
30}
31
32/// Context required to set the parameter's value.
33///
34/// Note that we do not strictly follow the PostgreSQL's semantics for each variant
35/// but only pick the minimum set of variants required for features like tab-completion.
36#[derive(Clone, Copy)]
37enum Context {
38    /// Used for immutable system parameters.
39    Internal,
40
41    /// Used for mutable system parameters.
42    // TODO: `postmaster` means that changes require a restart of the server. This is
43    // not accurate for all system parameters. Use lower contexts once we guarantee about
44    // the behavior of each parameter.
45    Postmaster,
46
47    /// Used for session variables.
48    // TODO: There might be variables that can only be set by superusers in the future.
49    // Should use `superuser` context then.
50    User,
51}
52
53impl WithDataType for Context {
54    fn default_data_type() -> DataType {
55        DataType::Varchar
56    }
57}
58
59impl ToOwnedDatum for Context {
60    fn to_owned_datum(self) -> Datum {
61        match self {
62            Context::Internal => "internal",
63            Context::Postmaster => "postmaster",
64            Context::User => "user",
65        }
66        .to_owned_datum()
67    }
68}
69
70#[system_catalog(table, "pg_catalog.pg_settings")]
71fn read_pg_settings(reader: &SysCatalogReaderImpl) -> Vec<PgSetting> {
72    let variables = (reader.config.read().show_all())
73        .into_iter()
74        .map(|info| PgSetting {
75            name: info.name,
76            setting: info.setting,
77            short_desc: info.description,
78            context: Context::User,
79        });
80
81    let system_params = (reader.system_params.load().get_all())
82        .into_iter()
83        .map(|info| PgSetting {
84            name: info.name.to_owned(),
85            setting: info.value,
86            short_desc: info.description.to_owned(),
87            context: if info.mutable {
88                Context::Postmaster
89            } else {
90                Context::Internal
91            },
92        });
93
94    variables.chain(system_params).collect()
95}
risingwave_frontend/catalog/system_catalog/pg_catalog/pg_settings.rs

risingwave_frontend/catalog/system_catalog/pg_catalog/
pg_settings.rs
