feat: support explain options (#1426)

Author: kysshsy

src/ast/mod.rs

@@ -3032,6 +3032,8 @@ pub enum Statement {
         statement: Box<Statement>,
         /// Optional output format of explain
         format: Option<AnalyzeFormat>,
+        /// Postgres style utility options, `(analyze, verbose true)`
+        options: Option<Vec<UtilityOption>>,
     },
     /// ```sql
     /// SAVEPOINT
@@ -3219,6 +3221,7 @@ impl fmt::Display for Statement {
                 analyze,
                 statement,
                 format,
+                options,
             } => {
                 write!(f, "{describe_alias} ")?;
 
@@ -3234,6 +3237,10 @@ impl fmt::Display for Statement {
                     write!(f, "FORMAT {format} ")?;
                 }
 
+                if let Some(options) = options {
+                    write!(f, "({}) ", display_comma_separated(options))?;
+                }
+
                 write!(f, "{statement}")
             }
             Statement::Query(s) => write!(f, "{s}"),
@@ -7125,6 +7132,47 @@ where
     }
 }
 
+/// Represents a single PostgreSQL utility option.
+///
+/// A utility option is a key-value pair where the key is an identifier (IDENT) and the value
+/// can be one of the following:
+/// - A number with an optional sign (`+` or `-`). Example: `+10`, `-10.2`, `3`
+/// - A non-keyword string. Example: `option1`, `'option2'`, `"option3"`
+/// - keyword: `TRUE`, `FALSE`, `ON` (`off` is also accept).
+/// - Empty. Example: `ANALYZE` (identifier only)
+///
+/// Utility options are used in various PostgreSQL DDL statements, including statements such as
+/// `CLUSTER`, `EXPLAIN`, `VACUUM`, and `REINDEX`. These statements format options as `( option [, ...] )`.
+///
+/// [CLUSTER](https://www.postgresql.org/docs/current/sql-cluster.html)
+/// [EXPLAIN](https://www.postgresql.org/docs/current/sql-explain.html)
+/// [VACUUM](https://www.postgresql.org/docs/current/sql-vacuum.html)
+/// [REINDEX](https://www.postgresql.org/docs/current/sql-reindex.html)
+///
+/// For example, the `EXPLAIN` AND `VACUUM` statements with options might look like this:
+/// ```sql
+/// EXPLAIN (ANALYZE, VERBOSE TRUE, FORMAT TEXT) SELECT * FROM my_table;
+///
+/// VACCUM (VERBOSE, ANALYZE ON, PARALLEL 10) my_table;
+/// ```
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct UtilityOption {
+    pub name: Ident,
+    pub arg: Option<Expr>,
+}
+
+impl Display for UtilityOption {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if let Some(ref arg) = self.arg {
+            write!(f, "{} {}", self.name, arg)
+        } else {
+            write!(f, "{}", self.name)
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/dialect/duckdb.rs

@@ -55,4 +55,10 @@ impl Dialect for DuckDbDialect {
     fn support_map_literal_syntax(&self) -> bool {
         true
     }
+
+    // DuckDB is compatible with PostgreSQL syntax for this statement,
+    // although not all features may be implemented.
+    fn supports_explain_with_utility_options(&self) -> bool {
+        true
+    }
 }

src/dialect/generic.rs

@@ -90,4 +90,8 @@ impl Dialect for GenericDialect {
     fn supports_create_index_with_clause(&self) -> bool {
         true
     }
+
+    fn supports_explain_with_utility_options(&self) -> bool {
+        true
+    }
 }

src/dialect/mod.rs

@@ -536,6 +536,10 @@ pub trait Dialect: Debug + Any {
     fn require_interval_qualifier(&self) -> bool {
         false
     }
+
+    fn supports_explain_with_utility_options(&self) -> bool {
+        false
+    }
 }
 
 /// This represents the operators for which precedence must be defined

src/dialect/postgresql.rs

@@ -166,6 +166,11 @@ impl Dialect for PostgreSqlDialect {
     fn supports_create_index_with_clause(&self) -> bool {
         true
     }
+
+    /// see <https://www.postgresql.org/docs/current/sql-explain.html>
+    fn supports_explain_with_utility_options(&self) -> bool {
+        true
+    }
 }
 
 pub fn parse_comment(parser: &mut Parser) -> Result<Statement, ParserError> {

src/parser/mod.rs

@@ -1277,6 +1277,29 @@ impl<'a> Parser<'a> {
         }
     }
 
+    pub fn parse_utility_options(&mut self) -> Result<Vec<UtilityOption>, ParserError> {
+        self.expect_token(&Token::LParen)?;
+        let options = self.parse_comma_separated(Self::parse_utility_option)?;
+        self.expect_token(&Token::RParen)?;
+
+        Ok(options)
+    }
+
+    fn parse_utility_option(&mut self) -> Result<UtilityOption, ParserError> {
+        let name = self.parse_identifier(false)?;
+
+        let next_token = self.peek_token();
+        if next_token == Token::Comma || next_token == Token::RParen {
+            return Ok(UtilityOption { name, arg: None });
+        }
+        let arg = self.parse_expr()?;
+
+        Ok(UtilityOption {
+            name,
+            arg: Some(arg),
+        })
+    }
+
     fn try_parse_expr_sub_query(&mut self) -> Result<Option<Expr>, ParserError> {
         if self
             .parse_one_of_keywords(&[Keyword::SELECT, Keyword::WITH])
@@ -8464,11 +8487,24 @@ impl<'a> Parser<'a> {
         &mut self,
         describe_alias: DescribeAlias,
     ) -> Result<Statement, ParserError> {
-        let analyze = self.parse_keyword(Keyword::ANALYZE);
-        let verbose = self.parse_keyword(Keyword::VERBOSE);
+        let mut analyze = false;
+        let mut verbose = false;
         let mut format = None;
-        if self.parse_keyword(Keyword::FORMAT) {
-            format = Some(self.parse_analyze_format()?);
+        let mut options = None;
+
+        // Note: DuckDB is compatible with PostgreSQL syntax for this statement,
+        // although not all features may be implemented.
+        if describe_alias == DescribeAlias::Explain
+            && self.dialect.supports_explain_with_utility_options()
+            && self.peek_token().token == Token::LParen
+        {
+            options = Some(self.parse_utility_options()?)
+        } else {
+            analyze = self.parse_keyword(Keyword::ANALYZE);
+            verbose = self.parse_keyword(Keyword::VERBOSE);
+            if self.parse_keyword(Keyword::FORMAT) {
+                format = Some(self.parse_analyze_format()?);
+            }
         }
 
         match self.maybe_parse(|parser| parser.parse_statement()) {
@@ -8481,6 +8517,7 @@ impl<'a> Parser<'a> {
                 verbose,
                 statement: Box::new(statement),
                 format,
+                options,
             }),
             _ => {
                 let hive_format =