risingwave_frontend/catalog/system_catalog/pg_catalog/
pg_description.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::Fields;
16use risingwave_frontend_macro::system_catalog;
17
18/// The catalog `pg_description` stores description.
19/// Ref: [`https://www.postgresql.org/docs/current/catalog-pg-description.html`]
20#[system_catalog(view, "pg_catalog.pg_description",
21    // objsubid = 0     => _row_id (hidden column)
22    // objsubid is NULL => table self
23    "SELECT objoid,
24        classoid,
25        CASE
26            WHEN objsubid = 0 THEN -1
27            WHEN objsubid IS NULL THEN 0
28            ELSE objsubid
29        END AS objsubid,
30        description
31    FROM rw_catalog.rw_description
32    WHERE description IS NOT NULL;"
33)]
34#[derive(Fields)]
35struct PgDescription {
36    objoid: i32,
37    classoid: i32,
38    objsubid: i32,
39    description: String,
40}