risingwave_frontend/expr/function_impl/
pg_relation_size.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_expr::{ExprError, Result, capture_context, function};
16
17use super::context::CATALOG_READER;
18use crate::catalog::CatalogReader;
19
20/// Computes the disk space used by one “fork” of the specified relation.
21#[function("pg_relation_size(int4) -> int8")]
22fn pg_relation_size(oid: i32) -> Result<i64> {
23    pg_relation_size_impl_captured(oid, "main")
24}
25
26#[function("pg_relation_size(int4, varchar) -> int8")]
27fn pg_relation_size_fork(oid: i32, fork: &str) -> Result<i64> {
28    pg_relation_size_impl_captured(oid, fork)
29}
30
31#[capture_context(CATALOG_READER)]
32fn pg_relation_size_impl(catalog: &CatalogReader, oid: i32, fork: &str) -> Result<i64> {
33    match fork {
34        "main" => {}
35        // These options are invalid in RW so we return 0 value as the result
36        "fsm" | "vm" | "init" => return Ok(0),
37        _ => return Err(ExprError::InvalidParam {
38            name: "fork",
39            reason:
40                "invalid fork name. Valid fork names are \"main\", \"fsm\", \"vm\", and \"init\""
41                    .into(),
42        }),
43    }
44    let catalog = catalog.read_guard();
45    if let Some(stats) = catalog.table_stats().table_stats.get(&(oid as u32)) {
46        Ok(stats.total_key_size + stats.total_value_size)
47    } else {
48        Ok(0)
49    }
50}
risingwave_frontend/expr/function_impl/pg_relation_size.rs

risingwave_frontend/expr/function_impl/
pg_relation_size.rs
