fix select * from pg_get_keywords() and impl pg_keywords

Signed-off-by: Runji Wang <[email protected]>

src/frontend/src/binder/relation/table_function.rs

@@ -16,18 +16,13 @@ use std::str::FromStr;
 
 use itertools::Itertools;
 use risingwave_common::bail_not_implemented;
-use risingwave_common::catalog::{
-    Field, Schema, PG_CATALOG_SCHEMA_NAME, RW_INTERNAL_TABLE_FUNCTION_NAME,
-};
+use risingwave_common::catalog::{Field, Schema, RW_INTERNAL_TABLE_FUNCTION_NAME};
 use risingwave_common::types::DataType;
 use risingwave_sqlparser::ast::{Function, FunctionArg, ObjectName, TableAlias};
 
 use super::watermark::is_watermark_func;
 use super::{Binder, Relation, Result, WindowTableFunctionKind};
 use crate::binder::bind_context::Clause;
-use crate::catalog::system_catalog::pg_catalog::{
-    PG_GET_KEYWORDS_FUNC_NAME, PG_KEYWORDS_TABLE_NAME,
-};
 use crate::error::ErrorCode;
 use crate::expr::{Expr, ExprImpl};
 
@@ -57,24 +52,6 @@ impl Binder {
                 }
                 return self.bind_internal_table(args, alias);
             }
-            if func_name.eq_ignore_ascii_case(PG_GET_KEYWORDS_FUNC_NAME)
-                || name.real_value().eq_ignore_ascii_case(
-                    format!("{}.{}", PG_CATALOG_SCHEMA_NAME, PG_GET_KEYWORDS_FUNC_NAME).as_str(),
-                )
-            {
-                if with_ordinality {
-                    bail_not_implemented!(
-                        "WITH ORDINALITY for internal/system table function {}",
-                        func_name
-                    );
-                }
-                return self.bind_relation_by_name_inner(
-                    Some(PG_CATALOG_SCHEMA_NAME),
-                    PG_KEYWORDS_TABLE_NAME,
-                    alias,
-                    None,
-                );
-            }
         }
         // window table functions (tumble/hop)
         if let Ok(kind) = WindowTableFunctionKind::from_str(func_name) {

src/frontend/src/catalog/system_catalog/pg_catalog/mod.rs

@@ -52,5 +52,3 @@ mod pg_trigger;
 mod pg_type;
 mod pg_user;
 mod pg_views;
-
-pub use pg_keywords::*;

src/frontend/src/catalog/system_catalog/pg_catalog/pg_keywords.rs

@@ -12,19 +12,60 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// The code is same as `expr/impl/src/table_function/pg_get_keywords.rs`.
+
 use risingwave_common::types::Fields;
 use risingwave_frontend_macro::system_catalog;
+use risingwave_sqlparser::keywords::{
+    ALL_KEYWORDS_INDEX, RESERVED_FOR_COLUMN_ALIAS, RESERVED_FOR_COLUMN_OR_TABLE_NAME,
+};
 
-pub const PG_KEYWORDS_TABLE_NAME: &str = "pg_keywords";
-pub const PG_GET_KEYWORDS_FUNC_NAME: &str = "pg_get_keywords";
+use crate::catalog::system_catalog::SysCatalogReaderImpl;
 
 /// The catalog `pg_keywords` stores keywords. `pg_get_keywords` returns the content of this table.
 /// Ref: [`https://www.postgresql.org/docs/15/functions-info.html`]
-// TODO: change to read reserved keywords here
-#[system_catalog(view, "pg_catalog.pg_keywords")]
+///
+/// # Example
+///
+/// ```slt
+/// query TTT
+/// select * from pg_keywords where word = 'add';
+/// ----
+/// add U unreserved
+/// ```
 #[derive(Fields)]
 struct PgKeywords {
+    #[primary_key]
     word: String,
-    catcode: String,
-    catdesc: String,
+    catcode: char,
+    catdesc: &'static str,
+}
+
+#[system_catalog(table, "pg_catalog.pg_keywords")]
+fn read_pg_keywords(_reader: &SysCatalogReaderImpl) -> Vec<PgKeywords> {
+    ALL_KEYWORDS_INDEX
+        .iter()
+        .map(|keyword| {
+            // FIXME: The current category is not correct. Many are different from the PostgreSQL.
+            let catcode = if !RESERVED_FOR_COLUMN_OR_TABLE_NAME.contains(keyword) {
+                'U'
+            } else if !RESERVED_FOR_COLUMN_ALIAS.contains(keyword) {
+                'C'
+            } else {
+                'R'
+            };
+            let catdesc = match catcode {
+                'U' => "unreserved",
+                'C' => "unreserved (cannot be function or type name)",
+                'T' => "reserved (can be function or type name)",
+                'R' => "reserved",
+                _ => unreachable!(),
+            };
+            PgKeywords {
+                word: keyword.to_string().to_lowercase(),
+                catcode,
+                catdesc,
+            }
+        })
+        .collect()
 }