Support parsing parenthesized wildcard (*) (#2123 )

PostgreSQL Tokenization: Fix unexpected characters after question mark being silently ignored (#2129 )
Added support for ALTER OPERATOR FAMILY syntax (#2125 )
2025-12-23 11:12:51 +00:00 · 2025-12-19 04:09:33 +00:00 · 2025-12-18 12:06:55 +00:00 · 2025-12-18 04:34:48 +00:00 · 2025-12-16 18:04:11 +00:00 · 2025-12-16 12:07:11 +00:00
26 changed files with 3304 additions and 725 deletions
--- a/dev/release/verify-release-candidate.sh
+++ b/dev/release/verify-release-candidate.sh
@ -124,7 +124,7 @@ test_source_distribution() {
  cargo build
  cargo test --all-features

-  if ( find -iname 'Cargo.toml' | xargs grep SNAPSHOT ); then
+  if ( find . -iname 'Cargo.toml' | xargs grep SNAPSHOT ); then
    echo "Cargo.toml version should not contain SNAPSHOT for releases"
    exit 1
  fi
--- a/src/ast/comments.rs
+++ b/src/ast/comments.rs
@ -0,0 +1,329 @@
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Provides a representation of source code comments in parsed SQL code.
+//!
+//! See [Comments::find] for an example.
+
+#[cfg(not(feature = "std"))]
+use alloc::{string::String, vec::Vec};
+
+use core::{
+    ops::{Bound, Deref, RangeBounds},
+    slice,
+};
+
+use crate::tokenizer::{Location, Span};
+
+/// An opaque container for comments from a parse SQL source code.
+#[derive(Default, Debug)]
+pub struct Comments(Vec<CommentWithSpan>);
+
+impl Comments {
+    /// Accepts `comment` if its the first or is located strictly after the
+    /// last accepted comment.  In other words, this method will skip the
+    /// comment if its comming out of order (as encountered in the parsed
+    /// source code.)
+    pub(crate) fn offer(&mut self, comment: CommentWithSpan) {
+        if self
+            .0
+            .last()
+            .map(|last| last.span < comment.span)
+            .unwrap_or(true)
+        {
+            self.0.push(comment);
+        }
+    }
+
+    /// Finds comments starting within the given location range. The order of
+    /// iterator reflects the order of the comments as encountered in the parsed
+    /// source code.
+    ///
+    /// # Example
+    /// ```rust
+    /// use sqlparser::{dialect::GenericDialect, parser::Parser, tokenizer::Location};
+    ///
+    /// let sql = r#"/*
+    ///  header comment ...
+    ///  ... spanning multiple lines
+    /// */
+    ///
+    ///  -- first statement
+    ///  SELECT 'hello' /* world */ FROM DUAL;
+    ///
+    ///  -- second statement
+    ///  SELECT 123 FROM DUAL;
+    ///
+    ///  -- trailing comment
+    /// "#;
+    ///
+    /// let (ast, comments) = Parser::parse_sql_with_comments(&GenericDialect, sql).unwrap();
+    ///
+    /// // all comments appearing before line seven, i.e. before the first statement itself
+    /// assert_eq!(
+    ///    &comments.find(..Location::new(7, 1)).map(|c| c.as_str()).collect::<Vec<_>>(),
+    ///    &["\n header comment ...\n ... spanning multiple lines\n", " first statement\n"]);
+    ///
+    /// // all comments appearing within the first statement
+    /// assert_eq!(
+    ///    &comments.find(Location::new(7, 1)..Location::new(8,1)).map(|c| c.as_str()).collect::<Vec<_>>(),
+    ///    &[" world "]);
+    ///
+    /// // all comments appearing within or after the first statement
+    /// assert_eq!(
+    ///    &comments.find(Location::new(7, 1)..).map(|c| c.as_str()).collect::<Vec<_>>(),
+    ///    &[" world ", " second statement\n", " trailing comment\n"]);
+    /// ```
+    ///
+    /// The [Spanned](crate::ast::Spanned) trait allows you to access location
+    /// information for certain AST nodes.
+    pub fn find<R: RangeBounds<Location>>(&self, range: R) -> Iter<'_> {
+        let (start, end) = (
+            self.start_index(range.start_bound()),
+            self.end_index(range.end_bound()),
+        );
+        debug_assert!((0..=self.0.len()).contains(&start));
+        debug_assert!((0..=self.0.len()).contains(&end));
+        // in case the user specified a reverse range
+        Iter(if start <= end {
+            self.0[start..end].iter()
+        } else {
+            self.0[0..0].iter()
+        })
+    }
+
+    /// Find the index of the first comment starting "before" the given location.
+    ///
+    /// The returned index is _inclusive_ and within the range of `0..=self.0.len()`.
+    fn start_index(&self, location: Bound<&Location>) -> usize {
+        match location {
+            Bound::Included(location) => {
+                match self.0.binary_search_by(|c| c.span.start.cmp(location)) {
+                    Ok(i) => i,
+                    Err(i) => i,
+                }
+            }
+            Bound::Excluded(location) => {
+                match self.0.binary_search_by(|c| c.span.start.cmp(location)) {
+                    Ok(i) => i + 1,
+                    Err(i) => i,
+                }
+            }
+            Bound::Unbounded => 0,
+        }
+    }
+
+    /// Find the index of the first comment starting "after" the given location.
+    ///
+    /// The returned index is _exclusive_ and within the range of `0..=self.0.len()`.
+    fn end_index(&self, location: Bound<&Location>) -> usize {
+        match location {
+            Bound::Included(location) => {
+                match self.0.binary_search_by(|c| c.span.start.cmp(location)) {
+                    Ok(i) => i + 1,
+                    Err(i) => i,
+                }
+            }
+            Bound::Excluded(location) => {
+                match self.0.binary_search_by(|c| c.span.start.cmp(location)) {
+                    Ok(i) => i,
+                    Err(i) => i,
+                }
+            }
+            Bound::Unbounded => self.0.len(),
+        }
+    }
+}
+
+impl From<Comments> for Vec<CommentWithSpan> {
+    fn from(comments: Comments) -> Self {
+        comments.0
+    }
+}
+
+/// A source code comment with information of its entire span.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CommentWithSpan {
+    /// The source code comment iself
+    pub comment: Comment,
+    /// The span of the comment including its markers
+    pub span: Span,
+}
+
+impl Deref for CommentWithSpan {
+    type Target = Comment;
+
+    fn deref(&self) -> &Self::Target {
+        &self.comment
+    }
+}
+
+/// A unified type of the different source code comment formats.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Comment {
+    /// A single line comment, typically introduced with a prefix and spanning
+    /// until end-of-line or end-of-file in the source code.
+    ///
+    /// Note: `content` will include the terminating new-line character, if any.
+    SingleLine { content: String, prefix: String },
+
+    /// A multi-line comment, typically enclosed in `/* .. */` markers. The
+    /// string represents the content excluding the markers.
+    MultiLine(String),
+}
+
+impl Comment {
+    /// Retrieves the content of the comment as string slice.
+    pub fn as_str(&self) -> &str {
+        match self {
+            Comment::SingleLine { content, prefix: _ } => content.as_str(),
+            Comment::MultiLine(content) => content.as_str(),
+        }
+    }
+}
+
+impl Deref for Comment {
+    type Target = str;
+
+    fn deref(&self) -> &Self::Target {
+        self.as_str()
+    }
+}
+
+/// An opaque iterator implementation over comments served by [Comments::find].
+pub struct Iter<'a>(slice::Iter<'a, CommentWithSpan>);
+
+impl<'a> Iterator for Iter<'a> {
+    type Item = &'a CommentWithSpan;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_find() {
+        let comments = {
+            // ```
+            // -- abc
+            //   /* hello */--, world
+            // /* def
+            //  ghi
+            //  jkl
+            // */
+            // ```
+            let mut c = Comments(Vec::new());
+            c.offer(CommentWithSpan {
+                comment: Comment::SingleLine {
+                    content: " abc".into(),
+                    prefix: "--".into(),
+                },
+                span: Span::new((1, 1).into(), (1, 7).into()),
+            });
+            c.offer(CommentWithSpan {
+                comment: Comment::MultiLine(" hello ".into()),
+                span: Span::new((2, 3).into(), (2, 14).into()),
+            });
+            c.offer(CommentWithSpan {
+                comment: Comment::SingleLine {
+                    content: ", world".into(),
+                    prefix: "--".into(),
+                },
+                span: Span::new((2, 14).into(), (2, 21).into()),
+            });
+            c.offer(CommentWithSpan {
+                comment: Comment::MultiLine(" def\n ghi\n jkl\n".into()),
+                span: Span::new((3, 3).into(), (7, 1).into()),
+            });
+            c
+        };
+
+        fn find<R: RangeBounds<Location>>(comments: &Comments, range: R) -> Vec<&str> {
+            comments.find(range).map(|c| c.as_str()).collect::<Vec<_>>()
+        }
+
+        // ~ end-points only --------------------------------------------------
+        assert_eq!(find(&comments, ..Location::new(0, 0)), Vec::<&str>::new());
+        assert_eq!(find(&comments, ..Location::new(2, 1)), vec![" abc"]);
+        assert_eq!(find(&comments, ..Location::new(2, 3)), vec![" abc"]);
+        assert_eq!(
+            find(&comments, ..=Location::new(2, 3)),
+            vec![" abc", " hello "]
+        );
+        assert_eq!(
+            find(&comments, ..=Location::new(2, 3)),
+            vec![" abc", " hello "]
+        );
+        assert_eq!(
+            find(&comments, ..Location::new(2, 15)),
+            vec![" abc", " hello ", ", world"]
+        );
+
+        // ~ start-points only ------------------------------------------------
+        assert_eq!(
+            find(&comments, Location::new(1000, 1000)..),
+            Vec::<&str>::new()
+        );
+        assert_eq!(
+            find(&comments, Location::new(2, 14)..),
+            vec![", world", " def\n ghi\n jkl\n"]
+        );
+        assert_eq!(
+            find(&comments, Location::new(2, 15)..),
+            vec![" def\n ghi\n jkl\n"]
+        );
+        assert_eq!(
+            find(&comments, Location::new(0, 0)..),
+            vec![" abc", " hello ", ", world", " def\n ghi\n jkl\n"]
+        );
+        assert_eq!(
+            find(&comments, Location::new(1, 1)..),
+            vec![" abc", " hello ", ", world", " def\n ghi\n jkl\n"]
+        );
+
+        // ~ ranges -----------------------------------------------------------
+        assert_eq!(
+            find(&comments, Location::new(2, 1)..Location::new(1, 1)),
+            Vec::<&str>::new()
+        );
+        assert_eq!(
+            find(&comments, Location::new(1, 1)..Location::new(2, 3)),
+            vec![" abc"]
+        );
+        assert_eq!(
+            find(&comments, Location::new(1, 1)..=Location::new(2, 3)),
+            vec![" abc", " hello "]
+        );
+        assert_eq!(
+            find(&comments, Location::new(1, 1)..=Location::new(2, 10)),
+            vec![" abc", " hello "]
+        );
+        assert_eq!(
+            find(&comments, Location::new(1, 1)..=Location::new(2, 14)),
+            vec![" abc", " hello ", ", world"]
+        );
+        assert_eq!(
+            find(&comments, Location::new(1, 1)..Location::new(2, 15)),
+            vec![" abc", " hello ", ", world"]
+        );
+
+        // ~ find everything --------------------------------------------------
+        assert_eq!(
+            find(&comments, ..),
+            vec![" abc", " hello ", ", world", " def\n ghi\n jkl\n"]
+        );
+    }
+}
--- a/src/ast/ddl.rs
+++ b/src/ast/ddl.rs
@ -61,7 +61,7 @@ use crate::tokenizer::{Span, Token};
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub struct IndexColumn {
    pub column: OrderByExpr,
-    pub operator_class: Option<Ident>,
+    pub operator_class: Option<ObjectName>,
 }

 impl From<Ident> for IndexColumn {
@ -371,10 +371,15 @@ pub enum AlterTableOperation {
    DropClusteringKey,
    SuspendRecluster,
    ResumeRecluster,
-    /// `REFRESH`
+    /// `REFRESH [ '<subpath>' ]`
    ///
-    /// Note: this is Snowflake specific for dynamic tables <https://docs.snowflake.com/en/sql-reference/sql/alter-table>
-    Refresh,
+    /// Note: this is Snowflake specific for dynamic/external tables
+    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-dynamic-table>
+    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-external-table>
+    Refresh {
+        /// Optional subpath for external table refresh
+        subpath: Option<String>,
+    },
    /// `SUSPEND`
    ///
    /// Note: this is Snowflake specific for dynamic tables <https://docs.snowflake.com/en/sql-reference/sql/alter-table>
@ -863,8 +868,12 @@ impl fmt::Display for AlterTableOperation {
                write!(f, "RESUME RECLUSTER")?;
                Ok(())
            }
-            AlterTableOperation::Refresh => {
-                write!(f, "REFRESH")
+            AlterTableOperation::Refresh { subpath } => {
+                write!(f, "REFRESH")?;
+                if let Some(path) = subpath {
+                    write!(f, " '{path}'")?;
+                }
+                Ok(())
            }
            AlterTableOperation::Suspend => {
                write!(f, "SUSPEND")
@ -995,6 +1004,103 @@ impl fmt::Display for AlterTypeOperation {
    }
 }

+/// `ALTER OPERATOR` statement
+/// See <https://www.postgresql.org/docs/current/sql-alteroperator.html>
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct AlterOperator {
+    /// Operator name (can be schema-qualified)
+    pub name: ObjectName,
+    /// Left operand type (`None` if no left operand)
+    pub left_type: Option<DataType>,
+    /// Right operand type
+    pub right_type: DataType,
+    /// The operation to perform
+    pub operation: AlterOperatorOperation,
+}
+
+/// An [AlterOperator] operation
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum AlterOperatorOperation {
+    /// `OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }`
+    OwnerTo(Owner),
+    /// `SET SCHEMA new_schema`
+    SetSchema { schema_name: ObjectName },
+    /// `SET ( options )`
+    Set {
+        /// List of operator options to set
+        options: Vec<OperatorOption>,
+    },
+}
+
+/// Option for `ALTER OPERATOR SET` operation
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum OperatorOption {
+    /// `RESTRICT = { res_proc | NONE }`
+    Restrict(Option<ObjectName>),
+    /// `JOIN = { join_proc | NONE }`
+    Join(Option<ObjectName>),
+    /// `COMMUTATOR = com_op`
+    Commutator(ObjectName),
+    /// `NEGATOR = neg_op`
+    Negator(ObjectName),
+    /// `HASHES`
+    Hashes,
+    /// `MERGES`
+    Merges,
+}
+
+impl fmt::Display for AlterOperator {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "ALTER OPERATOR {} (", self.name)?;
+        if let Some(left_type) = &self.left_type {
+            write!(f, "{}", left_type)?;
+        } else {
+            write!(f, "NONE")?;
+        }
+        write!(f, ", {}) {}", self.right_type, self.operation)
+    }
+}
+
+impl fmt::Display for AlterOperatorOperation {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::OwnerTo(owner) => write!(f, "OWNER TO {}", owner),
+            Self::SetSchema { schema_name } => write!(f, "SET SCHEMA {}", schema_name),
+            Self::Set { options } => {
+                write!(f, "SET (")?;
+                for (i, option) in options.iter().enumerate() {
+                    if i > 0 {
+                        write!(f, ", ")?;
+                    }
+                    write!(f, "{}", option)?;
+                }
+                write!(f, ")")
+            }
+        }
+    }
+}
+
+impl fmt::Display for OperatorOption {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::Restrict(Some(proc_name)) => write!(f, "RESTRICT = {}", proc_name),
+            Self::Restrict(None) => write!(f, "RESTRICT = NONE"),
+            Self::Join(Some(proc_name)) => write!(f, "JOIN = {}", proc_name),
+            Self::Join(None) => write!(f, "JOIN = NONE"),
+            Self::Commutator(op_name) => write!(f, "COMMUTATOR = {}", op_name),
+            Self::Negator(op_name) => write!(f, "NEGATOR = {}", op_name),
+            Self::Hashes => write!(f, "HASHES"),
+            Self::Merges => write!(f, "MERGES"),
+        }
+    }
+}
+
 /// An `ALTER COLUMN` (`Statement::AlterTable`) operation
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@ -1790,7 +1896,7 @@ impl fmt::Display for ColumnOption {
                        GeneratedAs::Always => "ALWAYS",
                        GeneratedAs::ByDefault => "BY DEFAULT",
                        // ExpStored goes with an expression, handled above
-                        GeneratedAs::ExpStored => unreachable!(),
+                        GeneratedAs::ExpStored => "",
                    };
                    write!(f, "GENERATED {when} AS IDENTITY")?;
                    if sequence_options.is_some() {
@ -2803,7 +2909,9 @@ impl fmt::Display for CreateTable {
            if let Some(file_format) = self.file_format {
                write!(f, " STORED AS {file_format}")?;
            }
-            write!(f, " LOCATION '{}'", self.location.as_ref().unwrap())?;
+            if let Some(location) = &self.location {
+                write!(f, " LOCATION '{location}'")?;
+            }
        }

        match &self.table_options {
@ -3878,8 +3986,11 @@ pub enum AlterTableType {
    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-iceberg-table>
    Iceberg,
    /// Dynamic table type
-    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-table>
+    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-dynamic-table>
    Dynamic,
+    /// External table type
+    /// <https://docs.snowflake.com/en/sql-reference/sql/alter-external-table>
+    External,
 }

 /// ALTER TABLE statement
@ -3909,6 +4020,7 @@ impl fmt::Display for AlterTable {
        match &self.table_type {
            Some(AlterTableType::Iceberg) => write!(f, "ALTER ICEBERG TABLE ")?,
            Some(AlterTableType::Dynamic) => write!(f, "ALTER DYNAMIC TABLE ")?,
+            Some(AlterTableType::External) => write!(f, "ALTER EXTERNAL TABLE ")?,
            None => write!(f, "ALTER TABLE ")?,
        }

@ -3979,18 +4091,8 @@ pub struct CreateOperator {
    pub left_arg: Option<DataType>,
    /// RIGHTARG parameter (right operand type)
    pub right_arg: Option<DataType>,
-    /// COMMUTATOR parameter (commutator operator)
-    pub commutator: Option<ObjectName>,
-    /// NEGATOR parameter (negator operator)
-    pub negator: Option<ObjectName>,
-    /// RESTRICT parameter (restriction selectivity function)
-    pub restrict: Option<ObjectName>,
-    /// JOIN parameter (join selectivity function)
-    pub join: Option<ObjectName>,
-    /// HASHES flag
-    pub hashes: bool,
-    /// MERGES flag
-    pub merges: bool,
+    /// Operator options (COMMUTATOR, NEGATOR, RESTRICT, JOIN, HASHES, MERGES)
+    pub options: Vec<OperatorOption>,
 }

 /// CREATE OPERATOR FAMILY statement
@ -4042,23 +4144,9 @@ impl fmt::Display for CreateOperator {
        if let Some(right_arg) = &self.right_arg {
            params.push(format!("RIGHTARG = {}", right_arg));
        }
-        if let Some(commutator) = &self.commutator {
-            params.push(format!("COMMUTATOR = {}", commutator));
-        }
-        if let Some(negator) = &self.negator {
-            params.push(format!("NEGATOR = {}", negator));
-        }
-        if let Some(restrict) = &self.restrict {
-            params.push(format!("RESTRICT = {}", restrict));
-        }
-        if let Some(join) = &self.join {
-            params.push(format!("JOIN = {}", join));
-        }
-        if self.hashes {
-            params.push("HASHES".to_string());
-        }
-        if self.merges {
-            params.push("MERGES".to_string());
+
+        for option in &self.options {
+            params.push(option.to_string());
        }

        write!(f, "{}", params.join(", "))?;
@ -4110,25 +4198,25 @@ impl fmt::Display for OperatorArgTypes {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum OperatorClassItem {
-    /// OPERATOR clause
+    /// `OPERATOR` clause
    Operator {
-        strategy_number: u32,
+        strategy_number: u64,
        operator_name: ObjectName,
        /// Optional operator argument types
        op_types: Option<OperatorArgTypes>,
-        /// FOR SEARCH or FOR ORDER BY
+        /// `FOR SEARCH` or `FOR ORDER BY`
        purpose: Option<OperatorPurpose>,
    },
-    /// FUNCTION clause
+    /// `FUNCTION` clause
    Function {
-        support_number: u32,
+        support_number: u64,
        /// Optional function argument types for the operator class
        op_types: Option<Vec<DataType>>,
        function_name: ObjectName,
        /// Function argument types
        argument_types: Vec<DataType>,
    },
-    /// STORAGE clause
+    /// `STORAGE` clause
    Storage { storage_type: DataType },
 }

@ -4325,3 +4413,189 @@ impl Spanned for DropOperatorClass {
        Span::empty()
    }
 }
+
+/// An item in an ALTER OPERATOR FAMILY ADD statement
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum OperatorFamilyItem {
+    /// `OPERATOR` clause
+    Operator {
+        strategy_number: u64,
+        operator_name: ObjectName,
+        /// Operator argument types
+        op_types: Vec<DataType>,
+        /// `FOR SEARCH` or `FOR ORDER BY`
+        purpose: Option<OperatorPurpose>,
+    },
+    /// `FUNCTION` clause
+    Function {
+        support_number: u64,
+        /// Optional operator argument types for the function
+        op_types: Option<Vec<DataType>>,
+        function_name: ObjectName,
+        /// Function argument types
+        argument_types: Vec<DataType>,
+    },
+}
+
+/// An item in an ALTER OPERATOR FAMILY DROP statement
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum OperatorFamilyDropItem {
+    /// `OPERATOR` clause
+    Operator {
+        strategy_number: u64,
+        /// Operator argument types
+        op_types: Vec<DataType>,
+    },
+    /// `FUNCTION` clause
+    Function {
+        support_number: u64,
+        /// Operator argument types for the function
+        op_types: Vec<DataType>,
+    },
+}
+
+impl fmt::Display for OperatorFamilyItem {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            OperatorFamilyItem::Operator {
+                strategy_number,
+                operator_name,
+                op_types,
+                purpose,
+            } => {
+                write!(
+                    f,
+                    "OPERATOR {strategy_number} {operator_name} ({})",
+                    display_comma_separated(op_types)
+                )?;
+                if let Some(purpose) = purpose {
+                    write!(f, " {purpose}")?;
+                }
+                Ok(())
+            }
+            OperatorFamilyItem::Function {
+                support_number,
+                op_types,
+                function_name,
+                argument_types,
+            } => {
+                write!(f, "FUNCTION {support_number}")?;
+                if let Some(types) = op_types {
+                    write!(f, " ({})", display_comma_separated(types))?;
+                }
+                write!(f, " {function_name}")?;
+                if !argument_types.is_empty() {
+                    write!(f, "({})", display_comma_separated(argument_types))?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl fmt::Display for OperatorFamilyDropItem {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            OperatorFamilyDropItem::Operator {
+                strategy_number,
+                op_types,
+            } => {
+                write!(
+                    f,
+                    "OPERATOR {strategy_number} ({})",
+                    display_comma_separated(op_types)
+                )
+            }
+            OperatorFamilyDropItem::Function {
+                support_number,
+                op_types,
+            } => {
+                write!(
+                    f,
+                    "FUNCTION {support_number} ({})",
+                    display_comma_separated(op_types)
+                )
+            }
+        }
+    }
+}
+
+/// `ALTER OPERATOR FAMILY` statement
+/// See <https://www.postgresql.org/docs/current/sql-alteropfamily.html>
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct AlterOperatorFamily {
+    /// Operator family name (can be schema-qualified)
+    pub name: ObjectName,
+    /// Index method (btree, hash, gist, gin, etc.)
+    pub using: Ident,
+    /// The operation to perform
+    pub operation: AlterOperatorFamilyOperation,
+}
+
+/// An [AlterOperatorFamily] operation
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum AlterOperatorFamilyOperation {
+    /// `ADD { OPERATOR ... | FUNCTION ... } [, ...]`
+    Add {
+        /// List of operator family items to add
+        items: Vec<OperatorFamilyItem>,
+    },
+    /// `DROP { OPERATOR ... | FUNCTION ... } [, ...]`
+    Drop {
+        /// List of operator family items to drop
+        items: Vec<OperatorFamilyDropItem>,
+    },
+    /// `RENAME TO new_name`
+    RenameTo { new_name: ObjectName },
+    /// `OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }`
+    OwnerTo(Owner),
+    /// `SET SCHEMA new_schema`
+    SetSchema { schema_name: ObjectName },
+}
+
+impl fmt::Display for AlterOperatorFamily {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "ALTER OPERATOR FAMILY {} USING {}",
+            self.name, self.using
+        )?;
+        write!(f, " {}", self.operation)
+    }
+}
+
+impl fmt::Display for AlterOperatorFamilyOperation {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            AlterOperatorFamilyOperation::Add { items } => {
+                write!(f, "ADD {}", display_comma_separated(items))
+            }
+            AlterOperatorFamilyOperation::Drop { items } => {
+                write!(f, "DROP {}", display_comma_separated(items))
+            }
+            AlterOperatorFamilyOperation::RenameTo { new_name } => {
+                write!(f, "RENAME TO {new_name}")
+            }
+            AlterOperatorFamilyOperation::OwnerTo(owner) => {
+                write!(f, "OWNER TO {owner}")
+            }
+            AlterOperatorFamilyOperation::SetSchema { schema_name } => {
+                write!(f, "SET SCHEMA {schema_name}")
+            }
+        }
+    }
+}
+
+impl Spanned for AlterOperatorFamily {
+    fn span(&self) -> Span {
+        Span::empty()
+    }
+}
--- a/src/ast/dml.rs
+++ b/src/ast/dml.rs
@ -24,13 +24,16 @@ use serde::{Deserialize, Serialize};
 #[cfg(feature = "visitor")]
 use sqlparser_derive::{Visit, VisitMut};

-use crate::display_utils::{indented_list, Indent, SpaceOrNewline};
+use crate::{
+    ast::display_separated,
+    display_utils::{indented_list, Indent, SpaceOrNewline},
+};

 use super::{
    display_comma_separated, helpers::attached_token::AttachedToken, query::InputFormatClause,
    Assignment, Expr, FromTable, Ident, InsertAliases, MysqlInsertPriority, ObjectName, OnInsert,
-    OrderByExpr, Query, SelectItem, Setting, SqliteOnConflict, TableObject, TableWithJoins,
-    UpdateTableFromKind,
+    OrderByExpr, Query, SelectInto, SelectItem, Setting, SqliteOnConflict, TableFactor,
+    TableObject, TableWithJoins, UpdateTableFromKind, Values,
 };

 /// INSERT statement.
@ -310,3 +313,334 @@ impl Display for Update {
        Ok(())
    }
 }
+
+/// A `MERGE` statement.
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct Merge {
+    /// The `MERGE` token that starts the statement.
+    pub merge_token: AttachedToken,
+    /// optional INTO keyword
+    pub into: bool,
+    /// Specifies the table to merge
+    pub table: TableFactor,
+    /// Specifies the table or subquery to join with the target table
+    pub source: TableFactor,
+    /// Specifies the expression on which to join the target table and source
+    pub on: Box<Expr>,
+    /// Specifies the actions to perform when values match or do not match.
+    pub clauses: Vec<MergeClause>,
+    // Specifies the output to save changes in MSSQL
+    pub output: Option<OutputClause>,
+}
+
+impl Display for Merge {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "MERGE{int} {table} USING {source} ",
+            int = if self.into { " INTO" } else { "" },
+            table = self.table,
+            source = self.source,
+        )?;
+        write!(f, "ON {on} ", on = self.on)?;
+        write!(f, "{}", display_separated(&self.clauses, " "))?;
+        if let Some(ref output) = self.output {
+            write!(f, " {output}")?;
+        }
+        Ok(())
+    }
+}
+
+/// A `WHEN` clause within a `MERGE` Statement
+///
+/// Example:
+/// ```sql
+/// WHEN NOT MATCHED BY SOURCE AND product LIKE '%washer%' THEN DELETE
+/// ```
+/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
+/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct MergeClause {
+    /// The `WHEN` token that starts the sub-expression.
+    pub when_token: AttachedToken,
+    pub clause_kind: MergeClauseKind,
+    pub predicate: Option<Expr>,
+    pub action: MergeAction,
+}
+
+impl Display for MergeClause {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let MergeClause {
+            when_token: _,
+            clause_kind,
+            predicate,
+            action,
+        } = self;
+
+        write!(f, "WHEN {clause_kind}")?;
+        if let Some(pred) = predicate {
+            write!(f, " AND {pred}")?;
+        }
+        write!(f, " THEN {action}")
+    }
+}
+
+/// Variant of `WHEN` clause used within a `MERGE` Statement.
+///
+/// Example:
+/// ```sql
+/// MERGE INTO T USING U ON FALSE WHEN MATCHED THEN DELETE
+/// ```
+/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
+/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum MergeClauseKind {
+    /// `WHEN MATCHED`
+    Matched,
+    /// `WHEN NOT MATCHED`
+    NotMatched,
+    /// `WHEN MATCHED BY TARGET`
+    ///
+    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+    NotMatchedByTarget,
+    /// `WHEN MATCHED BY SOURCE`
+    ///
+    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+    NotMatchedBySource,
+}
+
+impl Display for MergeClauseKind {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            MergeClauseKind::Matched => write!(f, "MATCHED"),
+            MergeClauseKind::NotMatched => write!(f, "NOT MATCHED"),
+            MergeClauseKind::NotMatchedByTarget => write!(f, "NOT MATCHED BY TARGET"),
+            MergeClauseKind::NotMatchedBySource => write!(f, "NOT MATCHED BY SOURCE"),
+        }
+    }
+}
+
+/// Underlying statement of a `WHEN` clause within a `MERGE` Statement
+///
+/// Example
+/// ```sql
+/// INSERT (product, quantity) VALUES(product, quantity)
+/// ```
+///
+/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
+/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+/// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/MERGE.html)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum MergeAction {
+    /// An `INSERT` clause
+    ///
+    /// Example:
+    /// ```sql
+    /// INSERT (product, quantity) VALUES(product, quantity)
+    /// ```
+    Insert(MergeInsertExpr),
+    /// An `UPDATE` clause
+    ///
+    /// Example:
+    /// ```sql
+    /// UPDATE SET quantity = T.quantity + S.quantity
+    /// ```
+    Update(MergeUpdateExpr),
+    /// A plain `DELETE` clause
+    Delete {
+        /// The `DELETE` token that starts the sub-expression.
+        delete_token: AttachedToken,
+    },
+}
+
+impl Display for MergeAction {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            MergeAction::Insert(insert) => {
+                write!(f, "INSERT {insert}")
+            }
+            MergeAction::Update(update) => {
+                write!(f, "UPDATE {update}")
+            }
+            MergeAction::Delete { .. } => {
+                write!(f, "DELETE")
+            }
+        }
+    }
+}
+
+/// The type of expression used to insert rows within a `MERGE` statement.
+///
+/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
+/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum MergeInsertKind {
+    /// The insert expression is defined from an explicit `VALUES` clause
+    ///
+    /// Example:
+    /// ```sql
+    /// INSERT VALUES(product, quantity)
+    /// ```
+    Values(Values),
+    /// The insert expression is defined using only the `ROW` keyword.
+    ///
+    /// Example:
+    /// ```sql
+    /// INSERT ROW
+    /// ```
+    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+    Row,
+}
+
+impl Display for MergeInsertKind {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            MergeInsertKind::Values(values) => {
+                write!(f, "{values}")
+            }
+            MergeInsertKind::Row => {
+                write!(f, "ROW")
+            }
+        }
+    }
+}
+
+/// The expression used to insert rows within a `MERGE` statement.
+///
+/// Examples
+/// ```sql
+/// INSERT (product, quantity) VALUES(product, quantity)
+/// INSERT ROW
+/// ```
+///
+/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
+/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+/// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/MERGE.html)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct MergeInsertExpr {
+    /// The `INSERT` token that starts the sub-expression.
+    pub insert_token: AttachedToken,
+    /// Columns (if any) specified by the insert.
+    ///
+    /// Example:
+    /// ```sql
+    /// INSERT (product, quantity) VALUES(product, quantity)
+    /// INSERT (product, quantity) ROW
+    /// ```
+    pub columns: Vec<ObjectName>,
+    /// The token, `[VALUES | ROW]` starting `kind`.
+    pub kind_token: AttachedToken,
+    /// The insert type used by the statement.
+    pub kind: MergeInsertKind,
+    /// An optional condition to restrict the insertion (Oracle specific)
+    pub insert_predicate: Option<Expr>,
+}
+
+impl Display for MergeInsertExpr {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if !self.columns.is_empty() {
+            write!(f, "({}) ", display_comma_separated(self.columns.as_slice()))?;
+        }
+        write!(f, "{}", self.kind)?;
+        if let Some(predicate) = self.insert_predicate.as_ref() {
+            write!(f, " WHERE {}", predicate)?;
+        }
+        Ok(())
+    }
+}
+
+/// The expression used to update rows within a `MERGE` statement.
+///
+/// Examples
+/// ```sql
+/// UPDATE SET quantity = T.quantity + S.quantity
+/// ```
+///
+/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
+/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
+/// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/MERGE.html)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct MergeUpdateExpr {
+    /// The `UPDATE` token that starts the sub-expression.
+    pub update_token: AttachedToken,
+    /// The update assiment expressions
+    pub assignments: Vec<Assignment>,
+    /// `where_clause` for the update (Oralce specific)
+    pub update_predicate: Option<Expr>,
+    /// `delete_clause` for the update "delete where" (Oracle specific)
+    pub delete_predicate: Option<Expr>,
+}
+
+impl Display for MergeUpdateExpr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "SET {}", display_comma_separated(&self.assignments))?;
+        if let Some(predicate) = self.update_predicate.as_ref() {
+            write!(f, " WHERE {predicate}")?;
+        }
+        if let Some(predicate) = self.delete_predicate.as_ref() {
+            write!(f, " DELETE WHERE {predicate}")?;
+        }
+        Ok(())
+    }
+}
+
+/// A `OUTPUT` Clause in the end of a `MERGE` Statement
+///
+/// Example:
+/// OUTPUT $action, deleted.* INTO dbo.temp_products;
+/// [mssql](https://learn.microsoft.com/en-us/sql/t-sql/queries/output-clause-transact-sql)
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum OutputClause {
+    Output {
+        output_token: AttachedToken,
+        select_items: Vec<SelectItem>,
+        into_table: Option<SelectInto>,
+    },
+    Returning {
+        returning_token: AttachedToken,
+        select_items: Vec<SelectItem>,
+    },
+}
+
+impl fmt::Display for OutputClause {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            OutputClause::Output {
+                output_token: _,
+                select_items,
+                into_table,
+            } => {
+                f.write_str("OUTPUT ")?;
+                display_comma_separated(select_items).fmt(f)?;
+                if let Some(into_table) = into_table {
+                    f.write_str(" ")?;
+                    into_table.fmt(f)?;
+                }
+                Ok(())
+            }
+            OutputClause::Returning {
+                returning_token: _,
+                select_items,
+            } => {
+                f.write_str("RETURNING ")?;
+                display_comma_separated(select_items).fmt(f)
+            }
+        }
+    }
+}
--- a/src/ast/helpers/stmt_data_loading.rs
+++ b/src/ast/helpers/stmt_data_loading.rs
@ -99,15 +99,15 @@ impl fmt::Display for StageParamsObject {

 impl fmt::Display for StageLoadSelectItem {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if self.alias.is_some() {
-            write!(f, "{}.", self.alias.as_ref().unwrap())?;
+        if let Some(alias) = &self.alias {
+            write!(f, "{alias}.")?;
        }
        write!(f, "${}", self.file_col_num)?;
-        if self.element.is_some() {
-            write!(f, ":{}", self.element.as_ref().unwrap())?;
+        if let Some(element) = &self.element {
+            write!(f, ":{element}")?;
        }
-        if self.item_as.is_some() {
-            write!(f, " AS {}", self.item_as.as_ref().unwrap())?;
+        if let Some(item_as) = &self.item_as {
+            write!(f, " AS {item_as}")?;
        }
        Ok(())
    }
--- a/src/ast/mod.rs
+++ b/src/ast/mod.rs
@ -59,7 +59,8 @@ pub use self::dcl::{
    AlterRoleOperation, CreateRole, ResetConfig, RoleOption, SecondaryRoles, SetConfigValue, Use,
 };
 pub use self::ddl::{
-    Alignment, AlterColumnOperation, AlterConnectorOwner, AlterIndexOperation,
+    Alignment, AlterColumnOperation, AlterConnectorOwner, AlterIndexOperation, AlterOperator,
+    AlterOperatorFamily, AlterOperatorFamilyOperation, AlterOperatorOperation,
    AlterPolicyOperation, AlterSchema, AlterSchemaOperation, AlterTable, AlterTableAlgorithm,
    AlterTableLock, AlterTableOperation, AlterTableType, AlterType, AlterTypeAddValue,
    AlterTypeAddValuePosition, AlterTypeOperation, AlterTypeRename, AlterTypeRenameValue,
@ -71,13 +72,17 @@ pub use self::ddl::{
    DropOperatorSignature, DropTrigger, GeneratedAs, GeneratedExpressionMode, IdentityParameters,
    IdentityProperty, IdentityPropertyFormatKind, IdentityPropertyKind, IdentityPropertyOrder,
    IndexColumn, IndexOption, IndexType, KeyOrIndexDisplay, Msck, NullsDistinctOption,
-    OperatorArgTypes, OperatorClassItem, OperatorPurpose, Owner, Partition, ProcedureParam,
-    ReferentialAction, RenameTableNameKind, ReplicaIdentity, TagsColumnOption, TriggerObjectKind,
-    Truncate, UserDefinedTypeCompositeAttributeDef, UserDefinedTypeInternalLength,
+    OperatorArgTypes, OperatorClassItem, OperatorFamilyDropItem, OperatorFamilyItem,
+    OperatorOption, OperatorPurpose, Owner, Partition, ProcedureParam, ReferentialAction,
+    RenameTableNameKind, ReplicaIdentity, TagsColumnOption, TriggerObjectKind, Truncate,
+    UserDefinedTypeCompositeAttributeDef, UserDefinedTypeInternalLength,
    UserDefinedTypeRangeOption, UserDefinedTypeRepresentation, UserDefinedTypeSqlDefinitionOption,
    UserDefinedTypeStorage, ViewColumnDef,
 };
-pub use self::dml::{Delete, Insert, Update};
+pub use self::dml::{
+    Delete, Insert, Merge, MergeAction, MergeClause, MergeClauseKind, MergeInsertExpr,
+    MergeInsertKind, MergeUpdateExpr, OutputClause, Update,
+};
 pub use self::operator::{BinaryOperator, UnaryOperator};
 pub use self::query::{
    AfterMatchSkip, ConnectBy, Cte, CteAsMaterialized, Distinct, EmptyMatchesMode,
@ -107,7 +112,7 @@ pub use self::trigger::{

 pub use self::value::{
    escape_double_quote_string, escape_quoted_string, DateTimeField, DollarQuotedString,
-    NormalizationForm, TrimWhereField, Value, ValueWithSpan,
+    NormalizationForm, QuoteDelimitedString, TrimWhereField, Value, ValueWithSpan,
 };

 use crate::ast::helpers::key_value_options::KeyValueOptions;
@ -133,6 +138,7 @@ mod query;
 mod spans;
 pub use spans::Spanned;

+pub mod comments;
 mod trigger;
 mod value;

@ -344,6 +350,12 @@ impl From<Vec<Ident>> for ObjectName {
    }
 }

+impl From<Ident> for ObjectName {
+    fn from(ident: Ident) -> Self {
+        ObjectName(vec![ObjectNamePart::Identifier(ident)])
+    }
+}
+
 impl fmt::Display for ObjectName {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", display_separated(&self.0, "."))
@ -3396,6 +3408,16 @@ pub enum Statement {
    /// ```
    AlterType(AlterType),
    /// ```sql
+    /// ALTER OPERATOR
+    /// ```
+    /// See [PostgreSQL](https://www.postgresql.org/docs/current/sql-alteroperator.html)
+    AlterOperator(AlterOperator),
+    /// ```sql
+    /// ALTER OPERATOR FAMILY
+    /// ```
+    /// See [PostgreSQL](https://www.postgresql.org/docs/current/sql-alteropfamily.html)
+    AlterOperatorFamily(AlterOperatorFamily),
+    /// ```sql
    /// ALTER ROLE
    /// ```
    AlterRole {
@ -4082,22 +4104,7 @@ pub enum Statement {
    /// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
    /// [MSSQL](https://learn.microsoft.com/en-us/sql/t-sql/statements/merge-transact-sql?view=sql-server-ver16)
-    Merge {
-        /// The `MERGE` token that starts the statement.
-        merge_token: AttachedToken,
-        /// optional INTO keyword
-        into: bool,
-        /// Specifies the table to merge
-        table: TableFactor,
-        /// Specifies the table or subquery to join with the target table
-        source: TableFactor,
-        /// Specifies the expression on which to join the target table and source
-        on: Box<Expr>,
-        /// Specifies the actions to perform when values match or do not match.
-        clauses: Vec<MergeClause>,
-        // Specifies the output to save changes in MSSQL
-        output: Option<OutputClause>,
-    },
+    Merge(Merge),
    /// ```sql
    /// CACHE [ FLAG ] TABLE <table_name> [ OPTIONS('K1' = 'V1', 'K2' = V2) ] [ AS ] [ <query> ]
    /// ```
@ -4971,6 +4978,10 @@ impl fmt::Display for Statement {
            Statement::AlterType(AlterType { name, operation }) => {
                write!(f, "ALTER TYPE {name} {operation}")
            }
+            Statement::AlterOperator(alter_operator) => write!(f, "{alter_operator}"),
+            Statement::AlterOperatorFamily(alter_operator_family) => {
+                write!(f, "{alter_operator_family}")
+            }
            Statement::AlterRole { name, operation } => {
                write!(f, "ALTER ROLE {name} {operation}")
            }
@ -5514,27 +5525,7 @@ impl fmt::Display for Statement {
            Statement::ReleaseSavepoint { name } => {
                write!(f, "RELEASE SAVEPOINT {name}")
            }
-            Statement::Merge {
-                merge_token: _,
-                into,
-                table,
-                source,
-                on,
-                clauses,
-                output,
-            } => {
-                write!(
-                    f,
-                    "MERGE{int} {table} USING {source} ",
-                    int = if *into { " INTO" } else { "" }
-                )?;
-                write!(f, "ON {on} ")?;
-                write!(f, "{}", display_separated(clauses, " "))?;
-                if let Some(output) = output {
-                    write!(f, " {output}")?;
-                }
-                Ok(())
-            }
+            Statement::Merge(merge) => merge.fmt(f),
            Statement::Cache {
                table_name,
                table_flag,
@ -8559,257 +8550,6 @@ impl fmt::Display for CopyLegacyCsvOption {
    }
 }

-/// Variant of `WHEN` clause used within a `MERGE` Statement.
-///
-/// Example:
-/// ```sql
-/// MERGE INTO T USING U ON FALSE WHEN MATCHED THEN DELETE
-/// ```
-/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
-/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub enum MergeClauseKind {
-    /// `WHEN MATCHED`
-    Matched,
-    /// `WHEN NOT MATCHED`
-    NotMatched,
-    /// `WHEN MATCHED BY TARGET`
-    ///
-    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-    NotMatchedByTarget,
-    /// `WHEN MATCHED BY SOURCE`
-    ///
-    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-    NotMatchedBySource,
-}
-
-impl Display for MergeClauseKind {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            MergeClauseKind::Matched => write!(f, "MATCHED"),
-            MergeClauseKind::NotMatched => write!(f, "NOT MATCHED"),
-            MergeClauseKind::NotMatchedByTarget => write!(f, "NOT MATCHED BY TARGET"),
-            MergeClauseKind::NotMatchedBySource => write!(f, "NOT MATCHED BY SOURCE"),
-        }
-    }
-}
-
-/// The type of expression used to insert rows within a `MERGE` statement.
-///
-/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
-/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub enum MergeInsertKind {
-    /// The insert expression is defined from an explicit `VALUES` clause
-    ///
-    /// Example:
-    /// ```sql
-    /// INSERT VALUES(product, quantity)
-    /// ```
-    Values(Values),
-    /// The insert expression is defined using only the `ROW` keyword.
-    ///
-    /// Example:
-    /// ```sql
-    /// INSERT ROW
-    /// ```
-    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-    Row,
-}
-
-impl Display for MergeInsertKind {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            MergeInsertKind::Values(values) => {
-                write!(f, "{values}")
-            }
-            MergeInsertKind::Row => {
-                write!(f, "ROW")
-            }
-        }
-    }
-}
-
-/// The expression used to insert rows within a `MERGE` statement.
-///
-/// Examples
-/// ```sql
-/// INSERT (product, quantity) VALUES(product, quantity)
-/// INSERT ROW
-/// ```
-///
-/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
-/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub struct MergeInsertExpr {
-    /// The `INSERT` token that starts the sub-expression.
-    pub insert_token: AttachedToken,
-    /// Columns (if any) specified by the insert.
-    ///
-    /// Example:
-    /// ```sql
-    /// INSERT (product, quantity) VALUES(product, quantity)
-    /// INSERT (product, quantity) ROW
-    /// ```
-    pub columns: Vec<Ident>,
-    /// The token, `[VALUES | ROW]` starting `kind`.
-    pub kind_token: AttachedToken,
-    /// The insert type used by the statement.
-    pub kind: MergeInsertKind,
-}
-
-impl Display for MergeInsertExpr {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if !self.columns.is_empty() {
-            write!(f, "({}) ", display_comma_separated(self.columns.as_slice()))?;
-        }
-        write!(f, "{}", self.kind)
-    }
-}
-
-/// Underlying statement of a when clause within a `MERGE` Statement
-///
-/// Example
-/// ```sql
-/// INSERT (product, quantity) VALUES(product, quantity)
-/// ```
-///
-/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
-/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub enum MergeAction {
-    /// An `INSERT` clause
-    ///
-    /// Example:
-    /// ```sql
-    /// INSERT (product, quantity) VALUES(product, quantity)
-    /// ```
-    Insert(MergeInsertExpr),
-    /// An `UPDATE` clause
-    ///
-    /// Example:
-    /// ```sql
-    /// UPDATE SET quantity = T.quantity + S.quantity
-    /// ```
-    Update {
-        /// The `UPDATE` token that starts the sub-expression.
-        update_token: AttachedToken,
-        assignments: Vec<Assignment>,
-    },
-    /// A plain `DELETE` clause
-    Delete {
-        /// The `DELETE` token that starts the sub-expression.
-        delete_token: AttachedToken,
-    },
-}
-
-impl Display for MergeAction {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            MergeAction::Insert(insert) => {
-                write!(f, "INSERT {insert}")
-            }
-            MergeAction::Update { assignments, .. } => {
-                write!(f, "UPDATE SET {}", display_comma_separated(assignments))
-            }
-            MergeAction::Delete { .. } => {
-                write!(f, "DELETE")
-            }
-        }
-    }
-}
-
-/// A when clause within a `MERGE` Statement
-///
-/// Example:
-/// ```sql
-/// WHEN NOT MATCHED BY SOURCE AND product LIKE '%washer%' THEN DELETE
-/// ```
-/// [Snowflake](https://docs.snowflake.com/en/sql-reference/sql/merge)
-/// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/dml-syntax#merge_statement)
-#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub struct MergeClause {
-    /// The `WHEN` token that starts the sub-expression.
-    pub when_token: AttachedToken,
-    pub clause_kind: MergeClauseKind,
-    pub predicate: Option<Expr>,
-    pub action: MergeAction,
-}
-
-impl Display for MergeClause {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let MergeClause {
-            when_token: _,
-            clause_kind,
-            predicate,
-            action,
-        } = self;
-
-        write!(f, "WHEN {clause_kind}")?;
-        if let Some(pred) = predicate {
-            write!(f, " AND {pred}")?;
-        }
-        write!(f, " THEN {action}")
-    }
-}
-
-/// A Output Clause in the end of a 'MERGE' Statement
-///
-/// Example:
-/// OUTPUT $action, deleted.* INTO dbo.temp_products;
-/// [mssql](https://learn.microsoft.com/en-us/sql/t-sql/queries/output-clause-transact-sql)
-#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
-pub enum OutputClause {
-    Output {
-        output_token: AttachedToken,
-        select_items: Vec<SelectItem>,
-        into_table: Option<SelectInto>,
-    },
-    Returning {
-        returning_token: AttachedToken,
-        select_items: Vec<SelectItem>,
-    },
-}
-
-impl fmt::Display for OutputClause {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            OutputClause::Output {
-                output_token: _,
-                select_items,
-                into_table,
-            } => {
-                f.write_str("OUTPUT ")?;
-                display_comma_separated(select_items).fmt(f)?;
-                if let Some(into_table) = into_table {
-                    f.write_str(" ")?;
-                    into_table.fmt(f)?;
-                }
-                Ok(())
-            }
-            OutputClause::Returning {
-                returning_token: _,
-                select_items,
-            } => {
-                f.write_str("RETURNING ")?;
-                display_comma_separated(select_items).fmt(f)
-            }
-        }
-    }
-}
-
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
@ -9814,8 +9554,8 @@ impl fmt::Display for ShowCharset {
        } else {
            write!(f, " CHARACTER SET")?;
        }
-        if self.filter.is_some() {
-            write!(f, " {}", self.filter.as_ref().unwrap())?;
+        if let Some(filter) = &self.filter {
+            write!(f, " {filter}")?;
        }
        Ok(())
    }
--- a/src/ast/spans.rs
+++ b/src/ast/spans.rs
@ -28,7 +28,7 @@ use core::iter;
 use crate::tokenizer::Span;

 use super::{
-    dcl::SecondaryRoles, value::ValueWithSpan, AccessExpr, AlterColumnOperation,
+    comments, dcl::SecondaryRoles, value::ValueWithSpan, AccessExpr, AlterColumnOperation,
    AlterIndexOperation, AlterTableOperation, Analyze, Array, Assignment, AssignmentTarget,
    AttachedToken, BeginEndStatements, CaseStatement, CloseCursor, ClusteredIndex, ColumnDef,
    ColumnOption, ColumnOptionDef, ConditionalStatementBlock, ConditionalStatements,
@ -38,15 +38,15 @@ use super::{
    FunctionArgumentClause, FunctionArgumentList, FunctionArguments, GroupByExpr, HavingBound,
    IfStatement, IlikeSelectItem, IndexColumn, Insert, Interpolate, InterpolateExpr, Join,
    JoinConstraint, JoinOperator, JsonPath, JsonPathElem, LateralView, LimitClause,
-    MatchRecognizePattern, Measure, MergeAction, MergeClause, MergeInsertExpr, MergeInsertKind,
-    NamedParenthesizedList, NamedWindowDefinition, ObjectName, ObjectNamePart, Offset, OnConflict,
-    OnConflictAction, OnInsert, OpenStatement, OrderBy, OrderByExpr, OrderByKind, OutputClause,
-    Partition, PivotValueSource, ProjectionSelect, Query, RaiseStatement, RaiseStatementValue,
-    ReferentialAction, RenameSelectItem, ReplaceSelectElement, ReplaceSelectItem, Select,
-    SelectInto, SelectItem, SetExpr, SqlOption, Statement, Subscript, SymbolDefinition, TableAlias,
-    TableAliasColumnDef, TableConstraint, TableFactor, TableObject, TableOptionsClustered,
-    TableWithJoins, Update, UpdateTableFromKind, Use, Value, Values, ViewColumnDef, WhileStatement,
-    WildcardAdditionalOptions, With, WithFill,
+    MatchRecognizePattern, Measure, Merge, MergeAction, MergeClause, MergeInsertExpr,
+    MergeInsertKind, MergeUpdateExpr, NamedParenthesizedList, NamedWindowDefinition, ObjectName,
+    ObjectNamePart, Offset, OnConflict, OnConflictAction, OnInsert, OpenStatement, OrderBy,
+    OrderByExpr, OrderByKind, OutputClause, Partition, PivotValueSource, ProjectionSelect, Query,
+    RaiseStatement, RaiseStatementValue, ReferentialAction, RenameSelectItem, ReplaceSelectElement,
+    ReplaceSelectItem, Select, SelectInto, SelectItem, SetExpr, SqlOption, Statement, Subscript,
+    SymbolDefinition, TableAlias, TableAliasColumnDef, TableConstraint, TableFactor, TableObject,
+    TableOptionsClustered, TableWithJoins, Update, UpdateTableFromKind, Use, Value, Values,
+    ViewColumnDef, WhileStatement, WildcardAdditionalOptions, With, WithFill,
 };

 /// Given an iterator of spans, return the [Span::union] of all spans.
@ -252,6 +252,7 @@ impl Spanned for Values {
 /// - [Statement::CreateSecret]
 /// - [Statement::CreateRole]
 /// - [Statement::AlterType]
+/// - [Statement::AlterOperator]
 /// - [Statement::AlterRole]
 /// - [Statement::AttachDatabase]
 /// - [Statement::AttachDuckDBDatabase]
@ -401,6 +402,8 @@ impl Spanned for Statement {
            ),
            // These statements need to be implemented
            Statement::AlterType { .. } => Span::empty(),
+            Statement::AlterOperator { .. } => Span::empty(),
+            Statement::AlterOperatorFamily { .. } => Span::empty(),
            Statement::AlterRole { .. } => Span::empty(),
            Statement::AlterSession { .. } => Span::empty(),
            Statement::AttachDatabase { .. } => Span::empty(),
@ -451,20 +454,7 @@ impl Spanned for Statement {
            Statement::Explain { .. } => Span::empty(),
            Statement::Savepoint { .. } => Span::empty(),
            Statement::ReleaseSavepoint { .. } => Span::empty(),
-            Statement::Merge {
-                merge_token,
-                into: _,
-                table: _,
-                source: _,
-                on,
-                clauses,
-                output,
-            } => union_spans(
-                [merge_token.0.span, on.span()]
-                    .into_iter()
-                    .chain(clauses.iter().map(Spanned::span))
-                    .chain(output.iter().map(Spanned::span)),
-            ),
+            Statement::Merge(merge) => merge.span(),
            Statement::Cache { .. } => Span::empty(),
            Statement::UNCache { .. } => Span::empty(),
            Statement::CreateSequence { .. } => Span::empty(),
@ -925,6 +915,17 @@ impl Spanned for Update {
    }
 }

+impl Spanned for Merge {
+    fn span(&self) -> Span {
+        union_spans(
+            [self.merge_token.0.span, self.on.span()]
+                .into_iter()
+                .chain(self.clauses.iter().map(Spanned::span))
+                .chain(self.output.iter().map(Spanned::span)),
+        )
+    }
+}
+
 impl Spanned for FromTable {
    fn span(&self) -> Span {
        match self {
@ -1145,7 +1146,7 @@ impl Spanned for AlterTableOperation {
            AlterTableOperation::DropClusteringKey => Span::empty(),
            AlterTableOperation::SuspendRecluster => Span::empty(),
            AlterTableOperation::ResumeRecluster => Span::empty(),
-            AlterTableOperation::Refresh => Span::empty(),
+            AlterTableOperation::Refresh { .. } => Span::empty(),
            AlterTableOperation::Suspend => Span::empty(),
            AlterTableOperation::Resume => Span::empty(),
            AlterTableOperation::Algorithm { .. } => Span::empty(),
@ -2419,12 +2420,7 @@ impl Spanned for MergeAction {
    fn span(&self) -> Span {
        match self {
            MergeAction::Insert(expr) => expr.span(),
-            MergeAction::Update {
-                update_token,
-                assignments,
-            } => union_spans(
-                core::iter::once(update_token.0.span).chain(assignments.iter().map(Spanned::span)),
-            ),
+            MergeAction::Update(expr) => expr.span(),
            MergeAction::Delete { delete_token } => delete_token.0.span,
        }
    }
@ -2442,7 +2438,19 @@ impl Spanned for MergeInsertExpr {
                },
            ]
            .into_iter()
-            .chain(self.columns.iter().map(|i| i.span)),
+            .chain(self.insert_predicate.iter().map(Spanned::span))
+            .chain(self.columns.iter().map(|i| i.span())),
+        )
+    }
+}
+
+impl Spanned for MergeUpdateExpr {
+    fn span(&self) -> Span {
+        union_spans(
+            core::iter::once(self.update_token.0.span)
+                .chain(self.assignments.iter().map(Spanned::span))
+                .chain(self.update_predicate.iter().map(Spanned::span))
+                .chain(self.delete_predicate.iter().map(Spanned::span)),
        )
    }
 }
@ -2470,6 +2478,12 @@ impl Spanned for OutputClause {
    }
 }

+impl Spanned for comments::CommentWithSpan {
+    fn span(&self) -> Span {
+        self.span
+    }
+}
+
 #[cfg(test)]
 pub mod tests {
    use crate::dialect::{Dialect, GenericDialect, SnowflakeDialect};
@ -2766,7 +2780,7 @@ WHERE id = 1
        assert_eq!(stmt_span.end, (16, 67).into());

        // ~ individual tokens within the statement
-        let Statement::Merge {
+        let Statement::Merge(Merge {
            merge_token,
            into: _,
            table: _,
@ -2774,7 +2788,7 @@ WHERE id = 1
            on: _,
            clauses,
            output,
-        } = &r[0]
+        }) = &r[0]
        else {
            panic!("not a MERGE statement");
        };
@ -2812,10 +2826,12 @@ WHERE id = 1
            clauses[1].when_token.0.span,
            Span::new(Location::new(12, 17), Location::new(12, 21))
        );
-        if let MergeAction::Update {
+        if let MergeAction::Update(MergeUpdateExpr {
            update_token,
            assignments: _,
-        } = &clauses[1].action
+            update_predicate: _,
+            delete_predicate: _,
+        }) = &clauses[1].action
        {
            assert_eq!(
                update_token.0.span,
@ -2888,7 +2904,7 @@ WHERE id = 1
        );

        // ~ individual tokens within the statement
-        if let Statement::Merge { output, .. } = &r[0] {
+        if let Statement::Merge(Merge { output, .. }) = &r[0] {
            if let Some(OutputClause::Returning {
                returning_token, ..
            }) = output
@ -2922,7 +2938,7 @@ WHERE id = 1
        );

        // ~ individual tokens within the statement
-        if let Statement::Merge { output, .. } = &r[0] {
+        if let Statement::Merge(Merge { output, .. }) = &r[0] {
            if let Some(OutputClause::Output { output_token, .. }) = output {
                assert_eq!(
                    output_token.0.span,
@ -2935,4 +2951,44 @@ WHERE id = 1
            panic!("not a MERGE statement");
        };
    }
+
+    #[test]
+    fn test_merge_statement_spans_with_update_predicates() {
+        let sql = r#"
+       MERGE INTO a USING b ON a.id = b.id
+        WHEN MATCHED THEN
+              UPDATE set a.x = a.x + b.x
+               WHERE b.x != 2
+              DELETE WHERE a.x <> 3"#;
+
+        let r = Parser::parse_sql(&crate::dialect::GenericDialect, sql).unwrap();
+        assert_eq!(1, r.len());
+
+        // ~ assert the span of the whole statement
+        let stmt_span = r[0].span();
+        assert_eq!(
+            stmt_span,
+            Span::new(Location::new(2, 8), Location::new(6, 36))
+        );
+    }
+
+    #[test]
+    fn test_merge_statement_spans_with_insert_predicate() {
+        let sql = r#"
+       MERGE INTO a USING b ON a.id = b.id
+        WHEN NOT MATCHED THEN
+            INSERT VALUES (b.x, b.y) WHERE b.x != 2
+-- qed
+"#;
+
+        let r = Parser::parse_sql(&crate::dialect::GenericDialect, sql).unwrap();
+        assert_eq!(1, r.len());
+
+        // ~ assert the span of the whole statement
+        let stmt_span = r[0].span();
+        assert_eq!(
+            stmt_span,
+            Span::new(Location::new(2, 8), Location::new(4, 52))
+        );
+    }
 }
--- a/src/ast/value.rs
+++ b/src/ast/value.rs
@ -167,6 +167,12 @@ pub enum Value {
    TripleDoubleQuotedRawStringLiteral(String),
    /// N'string value'
    NationalStringLiteral(String),
+    /// Quote delimited literal. Examples `Q'{ab'c}'`, `Q'|ab'c|'`, `Q'|ab|c|'`
+    /// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/Literals.html#GUID-1824CBAA-6E16-4921-B2A6-112FB02248DA)
+    QuoteDelimitedStringLiteral(QuoteDelimitedString),
+    /// "National" quote delimited literal. Examples `Q'{ab'c}'`, `Q'|ab'c|'`, `Q'|ab|c|'`
+    /// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/Literals.html#GUID-1824CBAA-6E16-4921-B2A6-112FB02248DA)
+    NationalQuoteDelimitedStringLiteral(QuoteDelimitedString),
    /// X'hex value'
    HexStringLiteral(String),

@ -207,6 +213,8 @@ impl Value {
            | Value::NationalStringLiteral(s)
            | Value::HexStringLiteral(s) => Some(s),
            Value::DollarQuotedString(s) => Some(s.value),
+            Value::QuoteDelimitedStringLiteral(s) => Some(s.value),
+            Value::NationalQuoteDelimitedStringLiteral(s) => Some(s.value),
            _ => None,
        }
    }
@ -242,6 +250,8 @@ impl fmt::Display for Value {
            Value::EscapedStringLiteral(v) => write!(f, "E'{}'", escape_escaped_string(v)),
            Value::UnicodeStringLiteral(v) => write!(f, "U&'{}'", escape_unicode_string(v)),
            Value::NationalStringLiteral(v) => write!(f, "N'{v}'"),
+            Value::QuoteDelimitedStringLiteral(v) => v.fmt(f),
+            Value::NationalQuoteDelimitedStringLiteral(v) => write!(f, "N{v}"),
            Value::HexStringLiteral(v) => write!(f, "X'{v}'"),
            Value::Boolean(v) => write!(f, "{v}"),
            Value::SingleQuotedByteStringLiteral(v) => write!(f, "B'{v}'"),
@ -279,6 +289,28 @@ impl fmt::Display for DollarQuotedString {
    }
 }

+/// A quote delimited string literal, e.g. `Q'_abc_'`.
+///
+/// See [Value::QuoteDelimitedStringLiteral] and/or
+/// [Value::NationalQuoteDelimitedStringLiteral].
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct QuoteDelimitedString {
+    /// the quote start character; i.e. the character _after_ the opening `Q'`
+    pub start_quote: char,
+    /// the string literal value itself
+    pub value: String,
+    /// the quote end character; i.e. the character _before_ the closing `'`
+    pub end_quote: char,
+}
+
+impl fmt::Display for QuoteDelimitedString {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Q'{}{}{}'", self.start_quote, self.value, self.end_quote)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Ord, PartialOrd, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
--- a/src/dialect/generic.rs
+++ b/src/dialect/generic.rs
@ -195,4 +195,8 @@ impl Dialect for GenericDialect {
    fn supports_interval_options(&self) -> bool {
        true
    }
+
+    fn supports_quote_delimited_string(&self) -> bool {
+        true
+    }
 }
--- a/src/dialect/mod.rs
+++ b/src/dialect/mod.rs
@ -603,7 +603,7 @@ pub trait Dialect: Debug + Any {
        false
    }

-    /// Return true if the dialect supports specifying multiple options
+    /// Returns true if the dialect supports specifying multiple options
    /// in a `CREATE TABLE` statement for the structure of the new table. For example:
    /// `CREATE TABLE t (a INT, b INT) AS SELECT 1 AS b, 2 AS a`
    fn supports_create_table_multi_schema_info_sources(&self) -> bool {
@ -1209,6 +1209,13 @@ pub trait Dialect: Debug + Any {
    fn supports_semantic_view_table_factor(&self) -> bool {
        false
    }
+
+    /// Support quote delimited string literals, e.g. `Q'{...}'`
+    ///
+    /// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/Literals.html#GUID-1824CBAA-6E16-4921-B2A6-112FB02248DA)
+    fn supports_quote_delimited_string(&self) -> bool {
+        false
+    }
 }

 /// This represents the operators for which precedence must be defined
--- a/src/dialect/mssql.rs
+++ b/src/dialect/mssql.rs
@ -21,14 +21,12 @@ use crate::ast::{
    GranteesType, IfStatement, Statement,
 };
 use crate::dialect::Dialect;
-use crate::keywords::{self, Keyword};
+use crate::keywords::Keyword;
 use crate::parser::{Parser, ParserError};
 use crate::tokenizer::Token;
 #[cfg(not(feature = "std"))]
 use alloc::{vec, vec::Vec};

-const RESERVED_FOR_COLUMN_ALIAS: &[Keyword] = &[Keyword::IF, Keyword::ELSE];
-
 /// A [`Dialect`] for [Microsoft SQL Server](https://www.microsoft.com/en-us/sql-server/)
 #[derive(Debug)]
 pub struct MsSqlDialect {}
@ -128,8 +126,22 @@ impl Dialect for MsSqlDialect {
        &[GranteesType::Public]
    }

-    fn is_column_alias(&self, kw: &Keyword, _parser: &mut Parser) -> bool {
-        !keywords::RESERVED_FOR_COLUMN_ALIAS.contains(kw) && !RESERVED_FOR_COLUMN_ALIAS.contains(kw)
+    fn is_select_item_alias(&self, explicit: bool, kw: &Keyword, parser: &mut Parser) -> bool {
+        match kw {
+            // List of keywords that cannot be used as select item aliases in MSSQL
+            // regardless of whether the alias is explicit or implicit
+            Keyword::IF | Keyword::ELSE => false,
+            _ => explicit || self.is_column_alias(kw, parser),
+        }
+    }
+
+    fn is_table_factor_alias(&self, explicit: bool, kw: &Keyword, parser: &mut Parser) -> bool {
+        match kw {
+            // List of keywords that cannot be used as table aliases in MSSQL
+            // regardless of whether the alias is explicit or implicit
+            Keyword::IF | Keyword::ELSE => false,
+            _ => explicit || self.is_table_alias(kw, parser),
+        }
    }

    fn parse_statement(&self, parser: &mut Parser) -> Option<Result<Statement, ParserError>> {
--- a/src/dialect/oracle.rs
+++ b/src/dialect/oracle.rs
@ -15,7 +15,14 @@
 // specific language governing permissions and limitations
 // under the License.

-use super::Dialect;
+use log::debug;
+
+use crate::{
+    parser::{Parser, ParserError},
+    tokenizer::Token,
+};
+
+use super::{Dialect, Precedence};

 /// A [`Dialect`] for [Oracle Databases](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/index.html)
 #[derive(Debug)]
@ -75,7 +82,21 @@ impl Dialect for OracleDialect {
        true
    }

+    fn get_next_precedence(&self, parser: &Parser) -> Option<Result<u8, ParserError>> {
+        let t = parser.peek_token();
+        debug!("get_next_precedence() {t:?}");
+
+        match t.token {
+            Token::StringConcat => Some(Ok(self.prec_value(Precedence::PlusMinus))),
+            _ => None,
+        }
+    }
+
    fn supports_group_by_expr(&self) -> bool {
        true
    }
+
+    fn supports_quote_delimited_string(&self) -> bool {
+        true
+    }
 }
--- a/src/dialect/snowflake.rs
+++ b/src/dialect/snowflake.rs
@ -221,6 +221,11 @@ impl Dialect for SnowflakeDialect {
            return Some(parse_alter_dynamic_table(parser));
        }

+        if parser.parse_keywords(&[Keyword::ALTER, Keyword::EXTERNAL, Keyword::TABLE]) {
+            // ALTER EXTERNAL TABLE
+            return Some(parse_alter_external_table(parser));
+        }
+
        if parser.parse_keywords(&[Keyword::ALTER, Keyword::SESSION]) {
            // ALTER SESSION
            let set = match parser.parse_one_of_keywords(&[Keyword::SET, Keyword::UNSET]) {
@ -619,7 +624,7 @@ fn parse_alter_dynamic_table(parser: &mut Parser) -> Result<Statement, ParserErr

    // Parse the operation (REFRESH, SUSPEND, or RESUME)
    let operation = if parser.parse_keyword(Keyword::REFRESH) {
-        AlterTableOperation::Refresh
+        AlterTableOperation::Refresh { subpath: None }
    } else if parser.parse_keyword(Keyword::SUSPEND) {
        AlterTableOperation::Suspend
    } else if parser.parse_keyword(Keyword::RESUME) {
@ -649,6 +654,45 @@ fn parse_alter_dynamic_table(parser: &mut Parser) -> Result<Statement, ParserErr
    }))
 }

+/// Parse snowflake alter external table.
+/// <https://docs.snowflake.com/en/sql-reference/sql/alter-external-table>
+fn parse_alter_external_table(parser: &mut Parser) -> Result<Statement, ParserError> {
+    let if_exists = parser.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
+    let table_name = parser.parse_object_name(true)?;
+
+    // Parse the operation (REFRESH for now)
+    let operation = if parser.parse_keyword(Keyword::REFRESH) {
+        // Optional subpath for refreshing specific partitions
+        let subpath = match parser.peek_token().token {
+            Token::SingleQuotedString(s) => {
+                parser.next_token();
+                Some(s)
+            }
+            _ => None,
+        };
+        AlterTableOperation::Refresh { subpath }
+    } else {
+        return parser.expected("REFRESH after ALTER EXTERNAL TABLE", parser.peek_token());
+    };
+
+    let end_token = if parser.peek_token_ref().token == Token::SemiColon {
+        parser.peek_token_ref().clone()
+    } else {
+        parser.get_current_token().clone()
+    };
+
+    Ok(Statement::AlterTable(AlterTable {
+        name: table_name,
+        if_exists,
+        only: false,
+        operations: vec![operation],
+        location: None,
+        on_cluster: None,
+        table_type: Some(AlterTableType::External),
+        end_token: AttachedToken(end_token),
+    }))
+}
+
 /// Parse snowflake alter session.
 /// <https://docs.snowflake.com/en/sql-reference/sql/alter-session>
 fn parse_alter_session(parser: &mut Parser, set: bool) -> Result<Statement, ParserError> {
--- a/src/keywords.rs
+++ b/src/keywords.rs
@ -67,6 +67,15 @@ macro_rules! define_keywords {
        pub const ALL_KEYWORDS: &[&str] = &[
            $($ident),*
        ];
+
+        impl core::fmt::Display for Keyword {
+            fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+                match self {
+                    Keyword::NoKeyword => write!(f, "NoKeyword"),
+                    $(Keyword::$ident => write!(f, "{}", $ident),)*
+                }
+            }
+        }
    };
 }

--- a/src/lib.rs
+++ b/src/lib.rs
@ -153,6 +153,7 @@
 // Splitting complex nodes (expressions, statements, types) into separate types
 // would bloat the API and hide intent. Extra memory is a worthwhile tradeoff.
 #![allow(clippy::large_enum_variant)]
+#![forbid(clippy::unreachable)]

 // Allow proc-macros to find this crate
 extern crate self as sqlparser;
--- a/src/parser/merge.rs
+++ b/src/parser/merge.rs
@ -0,0 +1,242 @@
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! SQL Parser for a `MERGE` statement
+
+#[cfg(not(feature = "std"))]
+use alloc::{boxed::Box, format, vec, vec::Vec};
+
+use crate::{
+    ast::{
+        Merge, MergeAction, MergeClause, MergeClauseKind, MergeInsertExpr, MergeInsertKind,
+        MergeUpdateExpr, ObjectName, OutputClause, SetExpr, Statement,
+    },
+    dialect::{BigQueryDialect, GenericDialect, MySqlDialect},
+    keywords::Keyword,
+    parser::IsOptional,
+    tokenizer::TokenWithSpan,
+};
+
+use super::{Parser, ParserError};
+
+impl Parser<'_> {
+    /// Parse a `MERGE` statement, returning a `Box`ed SetExpr
+    ///
+    /// This is used to reduce the size of the stack frames in debug builds
+    pub(super) fn parse_merge_setexpr_boxed(
+        &mut self,
+        merge_token: TokenWithSpan,
+    ) -> Result<Box<SetExpr>, ParserError> {
+        Ok(Box::new(SetExpr::Merge(self.parse_merge(merge_token)?)))
+    }
+
+    pub fn parse_merge(&mut self, merge_token: TokenWithSpan) -> Result<Statement, ParserError> {
+        let into = self.parse_keyword(Keyword::INTO);
+
+        let table = self.parse_table_factor()?;
+
+        self.expect_keyword_is(Keyword::USING)?;
+        let source = self.parse_table_factor()?;
+        self.expect_keyword_is(Keyword::ON)?;
+        let on = self.parse_expr()?;
+        let clauses = self.parse_merge_clauses()?;
+        let output = match self.parse_one_of_keywords(&[Keyword::OUTPUT, Keyword::RETURNING]) {
+            Some(keyword) => Some(self.parse_output(keyword, self.get_current_token().clone())?),
+            None => None,
+        };
+
+        Ok(Statement::Merge(Merge {
+            merge_token: merge_token.into(),
+            into,
+            table,
+            source,
+            on: Box::new(on),
+            clauses,
+            output,
+        }))
+    }
+
+    fn parse_merge_clauses(&mut self) -> Result<Vec<MergeClause>, ParserError> {
+        let mut clauses = vec![];
+        loop {
+            if !(self.parse_keyword(Keyword::WHEN)) {
+                break;
+            }
+            let when_token = self.get_current_token().clone();
+
+            let mut clause_kind = MergeClauseKind::Matched;
+            if self.parse_keyword(Keyword::NOT) {
+                clause_kind = MergeClauseKind::NotMatched;
+            }
+            self.expect_keyword_is(Keyword::MATCHED)?;
+
+            if matches!(clause_kind, MergeClauseKind::NotMatched)
+                && self.parse_keywords(&[Keyword::BY, Keyword::SOURCE])
+            {
+                clause_kind = MergeClauseKind::NotMatchedBySource;
+            } else if matches!(clause_kind, MergeClauseKind::NotMatched)
+                && self.parse_keywords(&[Keyword::BY, Keyword::TARGET])
+            {
+                clause_kind = MergeClauseKind::NotMatchedByTarget;
+            }
+
+            let predicate = if self.parse_keyword(Keyword::AND) {
+                Some(self.parse_expr()?)
+            } else {
+                None
+            };
+
+            self.expect_keyword_is(Keyword::THEN)?;
+
+            let merge_clause = match self.parse_one_of_keywords(&[
+                Keyword::UPDATE,
+                Keyword::INSERT,
+                Keyword::DELETE,
+            ]) {
+                Some(Keyword::UPDATE) => {
+                    if matches!(
+                        clause_kind,
+                        MergeClauseKind::NotMatched | MergeClauseKind::NotMatchedByTarget
+                    ) {
+                        return parser_err!(
+                            format_args!("UPDATE is not allowed in a {clause_kind} merge clause"),
+                            self.get_current_token().span.start
+                        );
+                    }
+
+                    let update_token = self.get_current_token().clone();
+                    self.expect_keyword_is(Keyword::SET)?;
+                    let assignments = self.parse_comma_separated(Parser::parse_assignment)?;
+                    let update_predicate = if self.parse_keyword(Keyword::WHERE) {
+                        Some(self.parse_expr()?)
+                    } else {
+                        None
+                    };
+                    let delete_predicate = if self.parse_keyword(Keyword::DELETE) {
+                        let _ = self.expect_keyword(Keyword::WHERE)?;
+                        Some(self.parse_expr()?)
+                    } else {
+                        None
+                    };
+                    MergeAction::Update(MergeUpdateExpr {
+                        update_token: update_token.into(),
+                        assignments,
+                        update_predicate,
+                        delete_predicate,
+                    })
+                }
+                Some(Keyword::DELETE) => {
+                    if matches!(
+                        clause_kind,
+                        MergeClauseKind::NotMatched | MergeClauseKind::NotMatchedByTarget
+                    ) {
+                        return parser_err!(
+                            format_args!("DELETE is not allowed in a {clause_kind} merge clause"),
+                            self.get_current_token().span.start
+                        );
+                    };
+
+                    let delete_token = self.get_current_token().clone();
+                    MergeAction::Delete {
+                        delete_token: delete_token.into(),
+                    }
+                }
+                Some(Keyword::INSERT) => {
+                    if !matches!(
+                        clause_kind,
+                        MergeClauseKind::NotMatched | MergeClauseKind::NotMatchedByTarget
+                    ) {
+                        return parser_err!(
+                            format_args!("INSERT is not allowed in a {clause_kind} merge clause"),
+                            self.get_current_token().span.start
+                        );
+                    };
+
+                    let insert_token = self.get_current_token().clone();
+                    let is_mysql = dialect_of!(self is MySqlDialect);
+
+                    let columns = self.parse_merge_clause_insert_columns(is_mysql)?;
+                    let (kind, kind_token) = if dialect_of!(self is BigQueryDialect | GenericDialect)
+                        && self.parse_keyword(Keyword::ROW)
+                    {
+                        (MergeInsertKind::Row, self.get_current_token().clone())
+                    } else {
+                        self.expect_keyword_is(Keyword::VALUES)?;
+                        let values_token = self.get_current_token().clone();
+                        let values = self.parse_values(is_mysql, false)?;
+                        (MergeInsertKind::Values(values), values_token)
+                    };
+                    let insert_predicate = if self.parse_keyword(Keyword::WHERE) {
+                        Some(self.parse_expr()?)
+                    } else {
+                        None
+                    };
+
+                    MergeAction::Insert(MergeInsertExpr {
+                        insert_token: insert_token.into(),
+                        columns,
+                        kind_token: kind_token.into(),
+                        kind,
+                        insert_predicate,
+                    })
+                }
+                _ => {
+                    return parser_err!(
+                        "expected UPDATE, DELETE or INSERT in merge clause",
+                        self.peek_token_ref().span.start
+                    );
+                }
+            };
+            clauses.push(MergeClause {
+                when_token: when_token.into(),
+                clause_kind,
+                predicate,
+                action: merge_clause,
+            });
+        }
+        Ok(clauses)
+    }
+
+    fn parse_merge_clause_insert_columns(
+        &mut self,
+        allow_empty: bool,
+    ) -> Result<Vec<ObjectName>, ParserError> {
+        self.parse_parenthesized_qualified_column_list(IsOptional::Optional, allow_empty)
+    }
+
+    fn parse_output(
+        &mut self,
+        start_keyword: Keyword,
+        start_token: TokenWithSpan,
+    ) -> Result<OutputClause, ParserError> {
+        let select_items = self.parse_projection()?;
+        let into_table = if start_keyword == Keyword::OUTPUT && self.peek_keyword(Keyword::INTO) {
+            self.expect_keyword_is(Keyword::INTO)?;
+            Some(self.parse_select_into()?)
+        } else {
+            None
+        };
+
+        Ok(if start_keyword == Keyword::OUTPUT {
+            OutputClause::Output {
+                output_token: start_token.into(),
+                select_items,
+                into_table,
+            }
+        } else {
+            OutputClause::Returning {
+                returning_token: start_token.into(),
+                select_items,
+            }
+        })
+    }
+}
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@ -29,10 +29,10 @@ use alloc::{
    vec,
    vec::Vec,
 };
-use core::iter::Peekable;
 use core::num::NonZeroU8;
 use core::str::Chars;
 use core::{cmp, fmt};
+use core::{iter::Peekable, str};

 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
@ -46,7 +46,10 @@ use crate::dialect::{
    SnowflakeDialect,
 };
 use crate::keywords::{Keyword, ALL_KEYWORDS, ALL_KEYWORDS_INDEX};
-use crate::{ast::DollarQuotedString, dialect::HiveDialect};
+use crate::{
+    ast::{DollarQuotedString, QuoteDelimitedString},
+    dialect::HiveDialect,
+};

 /// SQL Token enumeration
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
@ -98,6 +101,12 @@ pub enum Token {
    TripleDoubleQuotedRawStringLiteral(String),
    /// "National" string literal: i.e: N'string'
    NationalStringLiteral(String),
+    /// Quote delimited literal. Examples `Q'{ab'c}'`, `Q'|ab'c|'`, `Q'|ab|c|'`
+    /// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/Literals.html#GUID-1824CBAA-6E16-4921-B2A6-112FB02248DA)
+    QuoteDelimitedStringLiteral(QuoteDelimitedString),
+    /// "Nationa" quote delimited literal. Examples `NQ'{ab'c}'`, `NQ'|ab'c|'`, `NQ'|ab|c|'`
+    /// [Oracle](https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/Literals.html#GUID-1824CBAA-6E16-4921-B2A6-112FB02248DA)
+    NationalQuoteDelimitedStringLiteral(QuoteDelimitedString),
    /// "escaped" string literal, which are an extension to the SQL standard: i.e: e'first \n second' or E 'first \n second'
    EscapedStringLiteral(String),
    /// Unicode string literal: i.e: U&'first \000A second'
@ -292,6 +301,8 @@ impl fmt::Display for Token {
            Token::TripleDoubleQuotedString(ref s) => write!(f, "\"\"\"{s}\"\"\""),
            Token::DollarQuotedString(ref s) => write!(f, "{s}"),
            Token::NationalStringLiteral(ref s) => write!(f, "N'{s}'"),
+            Token::QuoteDelimitedStringLiteral(ref s) => s.fmt(f),
+            Token::NationalQuoteDelimitedStringLiteral(ref s) => write!(f, "N{s}"),
            Token::EscapedStringLiteral(ref s) => write!(f, "E'{s}'"),
            Token::UnicodeStringLiteral(ref s) => write!(f, "U&'{s}'"),
            Token::HexStringLiteral(ref s) => write!(f, "X'{s}'"),
@ -1032,6 +1043,18 @@ impl<'a> Tokenizer<'a> {
                                self.tokenize_single_quoted_string(chars, '\'', backslash_escape)?;
                            Ok(Some(Token::NationalStringLiteral(s)))
                        }
+                        Some(&q @ 'q') | Some(&q @ 'Q')
+                            if self.dialect.supports_quote_delimited_string() =>
+                        {
+                            chars.next(); // consume and check the next char
+                            if let Some('\'') = chars.peek() {
+                                self.tokenize_quote_delimited_string(chars, &[n, q])
+                                    .map(|s| Some(Token::NationalQuoteDelimitedStringLiteral(s)))
+                            } else {
+                                let s = self.tokenize_word(String::from_iter([n, q]), chars);
+                                Ok(Some(Token::make_word(&s, None)))
+                            }
+                        }
                        _ => {
                            // regular identifier starting with an "N"
                            let s = self.tokenize_word(n, chars);
@ -1039,6 +1062,16 @@ impl<'a> Tokenizer<'a> {
                        }
                    }
                }
+                q @ 'Q' | q @ 'q' if self.dialect.supports_quote_delimited_string() => {
+                    chars.next(); // consume and check the next char
+                    if let Some('\'') = chars.peek() {
+                        self.tokenize_quote_delimited_string(chars, &[q])
+                            .map(|s| Some(Token::QuoteDelimitedStringLiteral(s)))
+                    } else {
+                        let s = self.tokenize_word(q, chars);
+                        Ok(Some(Token::make_word(&s, None)))
+                    }
+                }
                // PostgreSQL accepts "escape" string constants, which are an extension to the SQL standard.
                x @ 'e' | x @ 'E' if self.dialect.supports_string_escape_constant() => {
                    let starting_loc = chars.location();
@ -1684,7 +1717,7 @@ impl<'a> Tokenizer<'a> {
                            }
                        }
                        Some('#') => self.consume_and_return(chars, Token::QuestionMarkSharp),
-                        _ => self.consume_and_return(chars, Token::Question),
+                        _ => Ok(Some(Token::Question)),
                    }
                }
                '?' => {
@ -1994,6 +2027,61 @@ impl<'a> Tokenizer<'a> {
        )
    }

+    /// Reads a quote delimited string expecting `chars.next()` to deliver a quote.
+    ///
+    /// See <https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/Literals.html#GUID-1824CBAA-6E16-4921-B2A6-112FB02248DA>
+    fn tokenize_quote_delimited_string(
+        &self,
+        chars: &mut State,
+        // the prefix that introduced the possible literal or word,
+        // e.g. "Q" or "nq"
+        literal_prefix: &[char],
+    ) -> Result<QuoteDelimitedString, TokenizerError> {
+        let literal_start_loc = chars.location();
+        chars.next();
+
+        let start_quote_loc = chars.location();
+        let (start_quote, end_quote) = match chars.next() {
+            None | Some(' ') | Some('\t') | Some('\r') | Some('\n') => {
+                return self.tokenizer_error(
+                    start_quote_loc,
+                    format!(
+                        "Invalid space, tab, newline, or EOF after '{}''",
+                        String::from_iter(literal_prefix)
+                    ),
+                );
+            }
+            Some(c) => (
+                c,
+                match c {
+                    '[' => ']',
+                    '{' => '}',
+                    '<' => '>',
+                    '(' => ')',
+                    c => c,
+                },
+            ),
+        };
+
+        // read the string literal until the "quote character" following a by literal quote
+        let mut value = String::new();
+        while let Some(ch) = chars.next() {
+            if ch == end_quote {
+                if let Some('\'') = chars.peek() {
+                    chars.next(); // ~ consume the quote
+                    return Ok(QuoteDelimitedString {
+                        start_quote,
+                        value,
+                        end_quote,
+                    });
+                }
+            }
+            value.push(ch);
+        }
+
+        self.tokenizer_error(literal_start_loc, "Unterminated string literal")
+    }
+
    /// Read a quoted string.
    fn tokenize_quoted_string(
        &self,
@ -4059,4 +4147,23 @@ mod tests {
            panic!("Tokenizer should have failed on {sql}, but it succeeded with {tokens:?}");
        }
    }
+
+    #[test]
+    fn tokenize_question_mark() {
+        let dialect = PostgreSqlDialect {};
+        let sql = "SELECT x ? y";
+        let tokens = Tokenizer::new(&dialect, sql).tokenize().unwrap();
+        compare(
+            tokens,
+            vec![
+                Token::make_keyword("SELECT"),
+                Token::Whitespace(Whitespace::Space),
+                Token::make_word("x", None),
+                Token::Whitespace(Whitespace::Space),
+                Token::Question,
+                Token::Whitespace(Whitespace::Space),
+                Token::make_word("y", None),
+            ],
+        )
+    }
 }
--- a/tests/sqlparser_bigquery.rs
+++ b/tests/sqlparser_bigquery.rs
@ -1806,15 +1806,16 @@ fn parse_merge() {
    );
    let insert_action = MergeAction::Insert(MergeInsertExpr {
        insert_token: AttachedToken::empty(),
-        columns: vec![Ident::new("product"), Ident::new("quantity")],
+        columns: vec![Ident::new("product").into(), Ident::new("quantity").into()],
        kind_token: AttachedToken::empty(),
        kind: MergeInsertKind::Values(Values {
            value_keyword: false,
            explicit_row: false,
            rows: vec![vec![Expr::value(number("1")), Expr::value(number("2"))]],
        }),
+        insert_predicate: None,
    });
-    let update_action = MergeAction::Update {
+    let update_action = MergeAction::Update(MergeUpdateExpr {
        update_token: AttachedToken::empty(),
        assignments: vec![
            Assignment {
@ -1826,17 +1827,19 @@ fn parse_merge() {
                value: Expr::value(number("2")),
            },
        ],
-    };
+        update_predicate: None,
+        delete_predicate: None,
+    });

    match bigquery_and_generic().verified_stmt(sql) {
-        Statement::Merge {
+        Statement::Merge(Merge {
            into,
            table,
            source,
            on,
            clauses,
            ..
-        } => {
+        }) => {
            assert!(!into);
            assert_eq!(
                TableFactor::Table {
@ -1917,9 +1920,13 @@ fn parse_merge() {
                        predicate: Some(Expr::value(number("1"))),
                        action: MergeAction::Insert(MergeInsertExpr {
                            insert_token: AttachedToken::empty(),
-                            columns: vec![Ident::new("product"), Ident::new("quantity"),],
+                            columns: vec![
+                                Ident::new("product").into(),
+                                Ident::new("quantity").into(),
+                            ],
                            kind_token: AttachedToken::empty(),
                            kind: MergeInsertKind::Row,
+                            insert_predicate: None,
                        })
                    },
                    MergeClause {
@ -1928,9 +1935,13 @@ fn parse_merge() {
                        predicate: None,
                        action: MergeAction::Insert(MergeInsertExpr {
                            insert_token: AttachedToken::empty(),
-                            columns: vec![Ident::new("product"), Ident::new("quantity"),],
+                            columns: vec![
+                                Ident::new("product").into(),
+                                Ident::new("quantity").into(),
+                            ],
                            kind_token: AttachedToken::empty(),
                            kind: MergeInsertKind::Row,
+                            insert_predicate: None,
                        })
                    },
                    MergeClause {
@ -1941,7 +1952,8 @@ fn parse_merge() {
                            insert_token: AttachedToken::empty(),
                            columns: vec![],
                            kind_token: AttachedToken::empty(),
-                            kind: MergeInsertKind::Row
+                            kind: MergeInsertKind::Row,
+                            insert_predicate: None,
                        })
                    },
                    MergeClause {
@ -1952,7 +1964,8 @@ fn parse_merge() {
                            insert_token: AttachedToken::empty(),
                            columns: vec![],
                            kind_token: AttachedToken::empty(),
-                            kind: MergeInsertKind::Row
+                            kind: MergeInsertKind::Row,
+                            insert_predicate: None,
                        })
                    },
                    MergeClause {
@ -1975,7 +1988,7 @@ fn parse_merge() {
                        predicate: None,
                        action: MergeAction::Insert(MergeInsertExpr {
                            insert_token: AttachedToken::empty(),
-                            columns: vec![Ident::new("a"), Ident::new("b"),],
+                            columns: vec![Ident::new("a").into(), Ident::new("b").into(),],
                            kind_token: AttachedToken::empty(),
                            kind: MergeInsertKind::Values(Values {
                                value_keyword: false,
@ -1984,7 +1997,8 @@ fn parse_merge() {
                                    Expr::value(number("1")),
                                    Expr::Identifier(Ident::new("DEFAULT")),
                                ]]
-                            })
+                            }),
+                            insert_predicate: None,
                        })
                    },
                    MergeClause {
@ -2002,7 +2016,8 @@ fn parse_merge() {
                                    Expr::value(number("1")),
                                    Expr::Identifier(Ident::new("DEFAULT")),
                                ]]
-                            })
+                            }),
+                            insert_predicate: None,
                        })
                    },
                ],
--- a/tests/sqlparser_comments.rs
+++ b/tests/sqlparser_comments.rs
@ -0,0 +1,75 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#![warn(clippy::all)]
+//! Test comment extraction from SQL source code.
+
+#[cfg(test)]
+use pretty_assertions::assert_eq;
+
+use sqlparser::{
+    ast::comments::{Comment, CommentWithSpan},
+    dialect::GenericDialect,
+    parser::Parser,
+    tokenizer::Span,
+};
+
+#[test]
+fn parse_sql_with_comments() {
+    let sql = r#"
+-- second line comment
+select * from /* inline comment after `from` */ dual;
+
+/*select
+some
+more*/
+
+  -- end-of-script-with-no-newline"#;
+
+    let comments = match Parser::parse_sql_with_comments(&GenericDialect, sql) {
+        Ok((_, comments)) => comments,
+        Err(e) => panic!("Invalid sql script: {e}"),
+    };
+
+    assert_eq!(
+        Vec::from(comments),
+        vec![
+            CommentWithSpan {
+                comment: Comment::SingleLine {
+                    content: " second line comment\n".into(),
+                    prefix: "--".into()
+                },
+                span: Span::new((2, 1).into(), (3, 1).into()),
+            },
+            CommentWithSpan {
+                comment: Comment::MultiLine(" inline comment after `from` ".into()),
+                span: Span::new((3, 15).into(), (3, 48).into()),
+            },
+            CommentWithSpan {
+                comment: Comment::MultiLine("select\nsome\nmore".into()),
+                span: Span::new((5, 1).into(), (7, 7).into())
+            },
+            CommentWithSpan {
+                comment: Comment::SingleLine {
+                    content: " end-of-script-with-no-newline".into(),
+                    prefix: "--".into()
+                },
+                span: Span::new((9, 3).into(), (9, 35).into()),
+            }
+        ]
+    );
+}
--- a/tests/sqlparser_common.rs
+++ b/tests/sqlparser_common.rs
@ -9793,22 +9793,22 @@ fn parse_merge() {
    let sql_no_into = "MERGE s.bar AS dest USING (SELECT * FROM s.foo) AS stg ON dest.D = stg.D AND dest.E = stg.E WHEN NOT MATCHED THEN INSERT (A, B, C) VALUES (stg.A, stg.B, stg.C) WHEN MATCHED AND dest.A = 'a' THEN UPDATE SET dest.F = stg.F, dest.G = stg.G WHEN MATCHED THEN DELETE";
    match (verified_stmt(sql), verified_stmt(sql_no_into)) {
        (
-            Statement::Merge {
+            Statement::Merge(Merge {
                into,
                table,
                source,
                on,
                clauses,
                ..
-            },
-            Statement::Merge {
+            }),
+            Statement::Merge(Merge {
                into: no_into,
                table: table_no_into,
                source: source_no_into,
                on: on_no_into,
                clauses: clauses_no_into,
                ..
-            },
+            }),
        ) => {
            assert!(into);
            assert!(!no_into);
@ -9921,7 +9921,11 @@ fn parse_merge() {
                        predicate: None,
                        action: MergeAction::Insert(MergeInsertExpr {
                            insert_token: AttachedToken::empty(),
-                            columns: vec![Ident::new("A"), Ident::new("B"), Ident::new("C")],
+                            columns: vec![
+                                Ident::new("A").into(),
+                                Ident::new("B").into(),
+                                Ident::new("C").into()
+                            ],
                            kind_token: AttachedToken::empty(),
                            kind: MergeInsertKind::Values(Values {
                                value_keyword: false,
@ -9941,6 +9945,7 @@ fn parse_merge() {
                                    ]),
                                ]]
                            }),
+                            insert_predicate: None,
                        }),
                    },
                    MergeClause {
@ -9956,7 +9961,7 @@ fn parse_merge() {
                                (Value::SingleQuotedString("a".to_string())).with_empty_span()
                            )),
                        }),
-                        action: MergeAction::Update {
+                        action: MergeAction::Update(MergeUpdateExpr {
                            update_token: AttachedToken::empty(),
                            assignments: vec![
                                Assignment {
@ -9980,7 +9985,9 @@ fn parse_merge() {
                                    ]),
                                },
                            ],
-                        },
+                            update_predicate: None,
+                            delete_predicate: None,
+                        }),
                    },
                    MergeClause {
                        when_token: AttachedToken::empty(),
@ -9999,6 +10006,45 @@ fn parse_merge() {

    let sql = "MERGE INTO s.bar AS dest USING newArrivals AS S ON (1 > 1) WHEN NOT MATCHED THEN INSERT VALUES (stg.A, stg.B, stg.C)";
    verified_stmt(sql);
+
+    // MERGE with predicates
+    let sql = "\
+MERGE INTO FOO \
+USING FOO_IMPORT \
+ON (FOO.ID = FOO_IMPORT.ID) \
+WHEN MATCHED THEN \
+UPDATE SET FOO.NAME = FOO_IMPORT.NAME \
+WHERE 1 = 1 \
+DELETE WHERE FOO.NAME LIKE '%.DELETE' \
+WHEN NOT MATCHED THEN \
+INSERT (ID, NAME) \
+VALUES (FOO_IMPORT.ID, UPPER(FOO_IMPORT.NAME)) \
+WHERE NOT FOO_IMPORT.NAME LIKE '%.DO_NOT_INSERT'";
+    all_dialects().verified_stmt(sql);
+
+    // MERGE with simple insert columns
+    let sql = "\
+MERGE INTO FOO USING FOO_IMPORT ON (FOO.ID = FOO_IMPORT.ID) \
+WHEN NOT MATCHED THEN \
+INSERT (ID, NAME) \
+VALUES (1, 'abc')";
+    all_dialects().verified_stmt(sql);
+
+    // MERGE with qualified insert columns
+    let sql = "\
+MERGE INTO FOO USING FOO_IMPORT ON (FOO.ID = FOO_IMPORT.ID) \
+WHEN NOT MATCHED THEN \
+INSERT (FOO.ID, FOO.NAME) \
+VALUES (1, 'abc')";
+    all_dialects().verified_stmt(sql);
+
+    // MERGE with schema qualified insert columns
+    let sql = "\
+MERGE INTO PLAYGROUND.FOO USING FOO_IMPORT ON (PLAYGROUND.FOO.ID = FOO_IMPORT.ID) \
+WHEN NOT MATCHED THEN \
+INSERT (PLAYGROUND.FOO.ID, PLAYGROUND.FOO.NAME) \
+VALUES (1, 'abc')";
+    all_dialects().verified_stmt(sql);
 }

 #[test]
@ -12074,6 +12120,8 @@ fn parse_execute_stored_procedure() {
        }
        _ => unreachable!(),
    }
+    // Test optional parentheses around procedure name
+    ms_and_generic().one_statement_parses_to("EXEC ('name')", "EXECUTE 'name'");
 }

 #[test]
@ -17905,3 +17953,22 @@ fn test_parse_set_session_authorization() {
        }))
    );
 }
+
+#[test]
+fn parse_select_parenthesized_wildcard() {
+    // Test SELECT DISTINCT(*) which uses a parenthesized wildcard
+    // The parentheses are syntactic sugar and get normalized to just *
+    let sql = "SELECT DISTINCT (*) FROM table1";
+    let canonical = "SELECT DISTINCT * FROM table1";
+    let select = all_dialects().verified_only_select_with_canonical(sql, canonical);
+    assert_eq!(select.distinct, Some(Distinct::Distinct));
+    assert_eq!(select.projection.len(), 1);
+    assert!(matches!(select.projection[0], SelectItem::Wildcard(_)));
+
+    // Also test without spaces: SELECT DISTINCT(*)
+    let sql_no_spaces = "SELECT DISTINCT(*) FROM table1";
+    let select2 = all_dialects().verified_only_select_with_canonical(sql_no_spaces, canonical);
+    assert_eq!(select2.distinct, Some(Distinct::Distinct));
+    assert_eq!(select2.projection.len(), 1);
+    assert!(matches!(select2.projection[0], SelectItem::Wildcard(_)));
+}
--- a/tests/sqlparser_hive.rs
+++ b/tests/sqlparser_hive.rs
@ -34,10 +34,12 @@ fn parse_table_create() {
    let sql = r#"CREATE TABLE IF NOT EXISTS db.table (a BIGINT, b STRING, c TIMESTAMP) PARTITIONED BY (d STRING, e TIMESTAMP) STORED AS ORC LOCATION 's3://...' TBLPROPERTIES ("prop" = "2", "asdf" = '1234', 'asdf' = "1234", "asdf" = 2)"#;
    let iof = r#"CREATE TABLE IF NOT EXISTS db.table (a BIGINT, b STRING, c TIMESTAMP) PARTITIONED BY (d STRING, e TIMESTAMP) STORED AS INPUTFORMAT 'org.apache.hadoop.hive.ql.io.orc.OrcInputFormat' OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat' LOCATION 's3://...'"#;
    let serdeproperties = r#"CREATE EXTERNAL TABLE IF NOT EXISTS db.table (a STRING, b STRING, c STRING) PARTITIONED BY (d STRING, e STRING) ROW FORMAT SERDE 'org.apache.hadoop.hive.serde.config' WITH SERDEPROPERTIES ('prop_a' = 'a', 'prop_b' = 'b') STORED AS TEXTFILE LOCATION 's3://...' TBLPROPERTIES ('prop_c' = 'c')"#;
+    let externaltable = r#"CREATE EXTERNAL TABLE t (c INT)"#;

    hive().verified_stmt(sql);
    hive().verified_stmt(iof);
    hive().verified_stmt(serdeproperties);
+    hive().verified_stmt(externaltable);
 }

 #[test]
--- a/tests/sqlparser_mssql.rs
+++ b/tests/sqlparser_mssql.rs
@ -2501,8 +2501,45 @@ fn test_tsql_no_semicolon_delimiter() {
 DECLARE @X AS NVARCHAR(MAX)='x'
 DECLARE @Y AS NVARCHAR(MAX)='y'
    "#;
-
    let stmts = tsql().parse_sql_statements(sql).unwrap();
    assert_eq!(stmts.len(), 2);
    assert!(stmts.iter().all(|s| matches!(s, Statement::Declare { .. })));
+
+    let sql = r#"
+SELECT col FROM tbl
+IF x=1
+  SELECT 1
+ELSE
+  SELECT 2
+    "#;
+    let stmts = tsql().parse_sql_statements(sql).unwrap();
+    assert_eq!(stmts.len(), 2);
+    assert!(matches!(&stmts[0], Statement::Query(_)));
+    assert!(matches!(&stmts[1], Statement::If(_)));
+}
+
+#[test]
+fn test_sql_keywords_as_table_aliases() {
+    // Some keywords that should not be parsed as an alias implicitly or explicitly
+    let reserved_kws = vec!["IF", "ELSE"];
+    for kw in reserved_kws {
+        for explicit in &["", "AS "] {
+            assert!(tsql()
+                .parse_sql_statements(&format!("SELECT * FROM tbl {explicit}{kw}"))
+                .is_err());
+        }
+    }
+}
+
+#[test]
+fn test_sql_keywords_as_column_aliases() {
+    // Some keywords that should not be parsed as an alias implicitly or explicitly
+    let reserved_kws = vec!["IF", "ELSE"];
+    for kw in reserved_kws {
+        for explicit in &["", "AS "] {
+            assert!(tsql()
+                .parse_sql_statements(&format!("SELECT col {explicit}{kw} FROM tbl"))
+                .is_err());
+        }
+    }
 }
--- a/tests/sqlparser_oracle.rs
+++ b/tests/sqlparser_oracle.rs
@ -0,0 +1,335 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+//! Test SQL syntax, specific to [sqlparser::dialect::OracleDialect].
+
+#[cfg(test)]
+use pretty_assertions::assert_eq;
+
+use sqlparser::{
+    ast::{BinaryOperator, Expr, Ident, QuoteDelimitedString, Value, ValueWithSpan},
+    dialect::OracleDialect,
+    parser::ParserError,
+    tokenizer::Span,
+};
+use test_utils::{all_dialects_where, expr_from_projection, number, TestedDialects};
+
+mod test_utils;
+
+fn oracle() -> TestedDialects {
+    TestedDialects::new(vec![Box::new(OracleDialect)])
+}
+
+/// Convenience constructor for [QuoteDelimitedstring].
+fn quote_delimited_string(
+    start_quote: char,
+    value: &'static str,
+    end_quote: char,
+) -> QuoteDelimitedString {
+    QuoteDelimitedString {
+        start_quote,
+        value: value.into(),
+        end_quote,
+    }
+}
+
+/// Oracle: `||` has a lower precedence than `*` and `/`
+#[test]
+fn muldiv_have_higher_precedence_than_strconcat() {
+    // ...............  A .. B ...... C .. D ...........
+    let sql = "SELECT 3 / 5 || 'asdf' || 7 * 9 FROM dual";
+    let select = oracle().verified_only_select(sql);
+    assert_eq!(1, select.projection.len());
+    assert_eq!(
+        expr_from_projection(&select.projection[0]),
+        // (C || D)
+        &Expr::BinaryOp {
+            // (A || B)
+            left: Box::new(Expr::BinaryOp {
+                // A
+                left: Box::new(Expr::BinaryOp {
+                    left: Box::new(Expr::Value(number("3").into())),
+                    op: BinaryOperator::Divide,
+                    right: Box::new(Expr::Value(number("5").into())),
+                }),
+                op: BinaryOperator::StringConcat,
+                right: Box::new(Expr::Value(ValueWithSpan {
+                    value: Value::SingleQuotedString("asdf".into()),
+                    span: Span::empty(),
+                })),
+            }),
+            op: BinaryOperator::StringConcat,
+            // D
+            right: Box::new(Expr::BinaryOp {
+                left: Box::new(Expr::Value(number("7").into())),
+                op: BinaryOperator::Multiply,
+                right: Box::new(Expr::Value(number("9").into())),
+            }),
+        }
+    );
+}
+
+/// Oracle: `+`, `-`, and `||` have the same precedence and parse from left-to-right
+#[test]
+fn plusminus_have_same_precedence_as_strconcat() {
+    // ................ A .. B .... C .. D ............
+    let sql = "SELECT 3 + 5 || '.3' || 7 - 9 FROM dual";
+    let select = oracle().verified_only_select(sql);
+    assert_eq!(1, select.projection.len());
+    assert_eq!(
+        expr_from_projection(&select.projection[0]),
+        // D
+        &Expr::BinaryOp {
+            left: Box::new(Expr::BinaryOp {
+                // B
+                left: Box::new(Expr::BinaryOp {
+                    // A
+                    left: Box::new(Expr::BinaryOp {
+                        left: Box::new(Expr::Value(number("3").into())),
+                        op: BinaryOperator::Plus,
+                        right: Box::new(Expr::Value(number("5").into())),
+                    }),
+                    op: BinaryOperator::StringConcat,
+                    right: Box::new(Expr::Value(ValueWithSpan {
+                        value: Value::SingleQuotedString(".3".into()),
+                        span: Span::empty(),
+                    })),
+                }),
+                op: BinaryOperator::StringConcat,
+                right: Box::new(Expr::Value(number("7").into())),
+            }),
+            op: BinaryOperator::Minus,
+            right: Box::new(Expr::Value(number("9").into()))
+        }
+    );
+}
+
+#[test]
+fn parse_quote_delimited_string() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    let sql = "SELECT Q'.abc.', \
+                      Q'Xab'cX', \
+                      Q'|abc'''|', \
+                      Q'{abc}d}', \
+                      Q'[]abc[]', \
+                      Q'<a'bc>', \
+                      Q'<<<a'bc>', \
+                      Q'('abc'('abc)', \
+                      Q'(abc'def))', \
+                      Q'(abc'def)))' \
+                 FROM dual";
+    let select = dialect.verified_only_select(sql);
+    assert_eq!(10, select.projection.len());
+    assert_eq!(
+        &Expr::Value(
+            Value::QuoteDelimitedStringLiteral(quote_delimited_string('.', "abc", '.'))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[0])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('X', "ab'c", 'X')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[1])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('|', "abc'''", '|')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[2])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('{', "abc}d", '}')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[3])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('[', "]abc[", ']')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[4])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('<', "a'bc", '>')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[5])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('<', "<<a'bc", '>')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[6])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('(', "'abc'('abc", ')')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[7])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('(', "abc'def)", ')')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[8])
+    );
+    assert_eq!(
+        &Expr::Value(
+            (Value::QuoteDelimitedStringLiteral(quote_delimited_string('(', "abc'def))", ')')))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[9])
+    );
+}
+
+#[test]
+fn parse_invalid_quote_delimited_strings() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    // ~ invalid quote delimiter
+    for q in [' ', '\t', '\r', '\n'] {
+        assert_eq!(
+            dialect.parse_sql_statements(&format!("SELECT Q'{q}abc{q}' FROM dual")),
+            Err(ParserError::TokenizerError(
+                "Invalid space, tab, newline, or EOF after 'Q'' at Line: 1, Column: 10".into()
+            )),
+            "with quote char {q:?}"
+        );
+    }
+    // ~ invalid eof after quote
+    assert_eq!(
+        dialect.parse_sql_statements("SELECT Q'"),
+        Err(ParserError::TokenizerError(
+            "Invalid space, tab, newline, or EOF after 'Q'' at Line: 1, Column: 10".into()
+        )),
+        "with EOF quote char"
+    );
+    // ~ unterminated string
+    assert_eq!(
+        dialect.parse_sql_statements("SELECT Q'|asdfa...."),
+        Err(ParserError::TokenizerError(
+            "Unterminated string literal at Line: 1, Column: 9".into()
+        )),
+        "with EOF quote char"
+    );
+}
+
+#[test]
+fn parse_quote_delimited_string_lowercase() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    let sql = "select q'!a'b'c!d!' from dual";
+    let select = dialect.verified_only_select_with_canonical(sql, "SELECT Q'!a'b'c!d!' FROM dual");
+    assert_eq!(1, select.projection.len());
+    assert_eq!(
+        &Expr::Value(
+            Value::QuoteDelimitedStringLiteral(quote_delimited_string('!', "a'b'c!d", '!'))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[0])
+    );
+}
+
+#[test]
+fn parse_quote_delimited_string_but_is_a_word() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    let sql = "SELECT q, quux, q.abc FROM dual q";
+    let select = dialect.verified_only_select(sql);
+    assert_eq!(3, select.projection.len());
+    assert_eq!(
+        &Expr::Identifier(Ident::with_span(Span::empty(), "q")),
+        expr_from_projection(&select.projection[0])
+    );
+    assert_eq!(
+        &Expr::Identifier(Ident::with_span(Span::empty(), "quux")),
+        expr_from_projection(&select.projection[1])
+    );
+    assert_eq!(
+        &Expr::CompoundIdentifier(vec![
+            Ident::with_span(Span::empty(), "q"),
+            Ident::with_span(Span::empty(), "abc")
+        ]),
+        expr_from_projection(&select.projection[2])
+    );
+}
+
+#[test]
+fn parse_national_quote_delimited_string() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    let sql = "SELECT NQ'.abc.' FROM dual";
+    let select = dialect.verified_only_select(sql);
+    assert_eq!(1, select.projection.len());
+    assert_eq!(
+        &Expr::Value(
+            Value::NationalQuoteDelimitedStringLiteral(quote_delimited_string('.', "abc", '.'))
+                .with_empty_span()
+        ),
+        expr_from_projection(&select.projection[0])
+    );
+}
+
+#[test]
+fn parse_national_quote_delimited_string_lowercase() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    for prefix in ["nq", "Nq", "nQ", "NQ"] {
+        let select = dialect.verified_only_select_with_canonical(
+            &format!("select {prefix}'!a'b'c!d!' from dual"),
+            "SELECT NQ'!a'b'c!d!' FROM dual",
+        );
+        assert_eq!(1, select.projection.len());
+        assert_eq!(
+            &Expr::Value(
+                Value::NationalQuoteDelimitedStringLiteral(quote_delimited_string(
+                    '!', "a'b'c!d", '!'
+                ))
+                .with_empty_span()
+            ),
+            expr_from_projection(&select.projection[0])
+        );
+    }
+}
+
+#[test]
+fn parse_national_quote_delimited_string_but_is_a_word() {
+    let dialect = all_dialects_where(|d| d.supports_quote_delimited_string());
+    let sql = "SELECT nq, nqoo, nq.abc FROM dual q";
+    let select = dialect.verified_only_select(sql);
+    assert_eq!(3, select.projection.len());
+    assert_eq!(
+        &Expr::Identifier(Ident::with_span(Span::empty(), "nq")),
+        expr_from_projection(&select.projection[0])
+    );
+    assert_eq!(
+        &Expr::Identifier(Ident::with_span(Span::empty(), "nqoo")),
+        expr_from_projection(&select.projection[1])
+    );
+    assert_eq!(
+        &Expr::CompoundIdentifier(vec![
+            Ident::with_span(Span::empty(), "nq"),
+            Ident::with_span(Span::empty(), "abc")
+        ]),
+        expr_from_projection(&select.projection[2])
+    );
+}
--- a/tests/sqlparser_postgres.rs
+++ b/tests/sqlparser_postgres.rs
@ -23,15 +23,11 @@
 mod test_utils;

 use helpers::attached_token::AttachedToken;
-use sqlparser::ast::{
-    DataType, DropBehavior, DropOperator, DropOperatorClass, DropOperatorSignature,
-};
-use sqlparser::tokenizer::Span;
-use test_utils::*;
-
 use sqlparser::ast::*;
 use sqlparser::dialect::{GenericDialect, PostgreSqlDialect};
 use sqlparser::parser::ParserError;
+use sqlparser::tokenizer::Span;
+use test_utils::*;

 #[test]
 fn parse_create_table_generated_always_as_identity() {
@ -2572,11 +2568,17 @@ fn parse_create_indices_with_operator_classes() {
        IndexType::SPGiST,
        IndexType::Custom("CustomIndexType".into()),
    ];
-    let operator_classes: [Option<Ident>; 4] = [
+    let operator_classes: [Option<ObjectName>; 4] = [
        None,
-        Some("gin_trgm_ops".into()),
-        Some("gist_trgm_ops".into()),
-        Some("totally_not_valid".into()),
+        Some(ObjectName(vec![ObjectNamePart::Identifier(Ident::new(
+            "gin_trgm_ops",
+        ))])),
+        Some(ObjectName(vec![ObjectNamePart::Identifier(Ident::new(
+            "gist_trgm_ops",
+        ))])),
+        Some(ObjectName(vec![ObjectNamePart::Identifier(Ident::new(
+            "totally_not_valid",
+        ))])),
    ];

    for expected_index_type in indices {
@ -2713,6 +2715,36 @@ fn parse_create_indices_with_operator_classes() {
    }
 }

+#[test]
+fn parse_create_index_with_schema_qualified_operator_class() {
+    let sql = "CREATE INDEX my_index ON my_table USING HNSW (embedding public.vector_cosine_ops)";
+
+    match pg().verified_stmt(sql) {
+        Statement::CreateIndex(CreateIndex { columns, .. }) => {
+            assert_eq!(1, columns.len());
+            let idx_col = &columns[0];
+
+            // Verify the column name
+            match &idx_col.column.expr {
+                Expr::Identifier(ident) => {
+                    assert_eq!("embedding", ident.value);
+                }
+                _ => panic!("Expected identifier expression"),
+            }
+
+            // Verify the schema-qualified operator class
+            assert_eq!(
+                Some(ObjectName(vec![
+                    ObjectNamePart::Identifier(Ident::new("public")),
+                    ObjectNamePart::Identifier(Ident::new("vector_cosine_ops")),
+                ])),
+                idx_col.operator_class
+            );
+        }
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn parse_create_bloom() {
    let sql =
@ -6715,24 +6747,26 @@ fn parse_create_operator() {
                length: 255,
                unit: None
            }))),
-            commutator: Some(ObjectName::from(vec![
-                Ident::new("schema"),
-                Ident::new(">")
-            ])),
-            negator: Some(ObjectName::from(vec![
-                Ident::new("schema"),
-                Ident::new("<=")
-            ])),
-            restrict: Some(ObjectName::from(vec![
-                Ident::new("myschema"),
-                Ident::new("sel_func")
-            ])),
-            join: Some(ObjectName::from(vec![
-                Ident::new("myschema"),
-                Ident::new("join_func")
-            ])),
-            hashes: true,
-            merges: true,
+            options: vec![
+                OperatorOption::Commutator(ObjectName::from(vec![
+                    Ident::new("schema"),
+                    Ident::new(">")
+                ])),
+                OperatorOption::Negator(ObjectName::from(vec![
+                    Ident::new("schema"),
+                    Ident::new("<=")
+                ])),
+                OperatorOption::Restrict(Some(ObjectName::from(vec![
+                    Ident::new("myschema"),
+                    Ident::new("sel_func")
+                ]))),
+                OperatorOption::Join(Some(ObjectName::from(vec![
+                    Ident::new("myschema"),
+                    Ident::new("join_func")
+                ]))),
+                OperatorOption::Hashes,
+                OperatorOption::Merges,
+            ],
        })
    );

@ -6748,12 +6782,7 @@ fn parse_create_operator() {
                is_procedure: false,
                left_arg: None,
                right_arg: None,
-                commutator: None,
-                negator: None,
-                restrict: None,
-                join: None,
-                hashes: false,
-                merges: false,
+                options: vec![],
            })
        );
    }
@ -6778,13 +6807,9 @@ fn parse_create_operator() {
        ),
    ] {
        match pg().verified_stmt(&format!("CREATE OPERATOR {name} (FUNCTION = f)")) {
-            Statement::CreateOperator(CreateOperator {
-                name,
-                hashes: false,
-                merges: false,
-                ..
-            }) => {
+            Statement::CreateOperator(CreateOperator { name, options, .. }) => {
                assert_eq!(name, expected_name);
+                assert!(options.is_empty());
            }
            _ => unreachable!(),
        }
@ -6920,6 +6945,592 @@ fn parse_drop_operator() {
    assert!(pg().parse_sql_statements(sql).is_err());
 }

+#[test]
+fn parse_alter_operator() {
+    use sqlparser::ast::{AlterOperator, AlterOperatorOperation, OperatorOption, Owner};
+
+    // Test ALTER OPERATOR ... OWNER TO with different owner types
+    for (owner_sql, owner_ast) in [
+        ("joe", Owner::Ident(Ident::new("joe"))),
+        ("CURRENT_USER", Owner::CurrentUser),
+        ("CURRENT_ROLE", Owner::CurrentRole),
+        ("SESSION_USER", Owner::SessionUser),
+    ] {
+        for (op_name, op_name_ast, left_type_sql, left_type_ast, right_type_sql, right_type_ast) in [
+            (
+                "+",
+                ObjectName::from(vec![Ident::new("+")]),
+                "INTEGER",
+                Some(DataType::Integer(None)),
+                "INTEGER",
+                DataType::Integer(None),
+            ),
+            (
+                "~",
+                ObjectName::from(vec![Ident::new("~")]),
+                "NONE",
+                None,
+                "BIT",
+                DataType::Bit(None),
+            ),
+            (
+                "@@",
+                ObjectName::from(vec![Ident::new("@@")]),
+                "TEXT",
+                Some(DataType::Text),
+                "TEXT",
+                DataType::Text,
+            ),
+        ] {
+            let sql = format!(
+                "ALTER OPERATOR {} ({}, {}) OWNER TO {}",
+                op_name, left_type_sql, right_type_sql, owner_sql
+            );
+            assert_eq!(
+                pg_and_generic().verified_stmt(&sql),
+                Statement::AlterOperator(AlterOperator {
+                    name: op_name_ast.clone(),
+                    left_type: left_type_ast.clone(),
+                    right_type: right_type_ast.clone(),
+                    operation: AlterOperatorOperation::OwnerTo(owner_ast.clone()),
+                })
+            );
+        }
+    }
+
+    // Test ALTER OPERATOR ... SET SCHEMA
+    for (op_name, op_name_ast, schema_name, schema_name_ast) in [
+        (
+            "+",
+            ObjectName::from(vec![Ident::new("+")]),
+            "new_schema",
+            ObjectName::from(vec![Ident::new("new_schema")]),
+        ),
+        (
+            "myschema.@@",
+            ObjectName::from(vec![Ident::new("myschema"), Ident::new("@@")]),
+            "other_schema",
+            ObjectName::from(vec![Ident::new("other_schema")]),
+        ),
+    ] {
+        let sql = format!(
+            "ALTER OPERATOR {} (TEXT, TEXT) SET SCHEMA {}",
+            op_name, schema_name
+        );
+        assert_eq!(
+            pg_and_generic().verified_stmt(&sql),
+            Statement::AlterOperator(AlterOperator {
+                name: op_name_ast,
+                left_type: Some(DataType::Text),
+                right_type: DataType::Text,
+                operation: AlterOperatorOperation::SetSchema {
+                    schema_name: schema_name_ast,
+                },
+            })
+        );
+    }
+
+    // Test ALTER OPERATOR ... SET with RESTRICT and JOIN
+    for (restrict_val, restrict_ast, join_val, join_ast) in [
+        (
+            "_int_contsel",
+            Some(ObjectName::from(vec![Ident::new("_int_contsel")])),
+            "_int_contjoinsel",
+            Some(ObjectName::from(vec![Ident::new("_int_contjoinsel")])),
+        ),
+        (
+            "NONE",
+            None,
+            "my_joinsel",
+            Some(ObjectName::from(vec![Ident::new("my_joinsel")])),
+        ),
+        (
+            "my_sel",
+            Some(ObjectName::from(vec![Ident::new("my_sel")])),
+            "NONE",
+            None,
+        ),
+    ] {
+        let sql = format!(
+            "ALTER OPERATOR && (TEXT, TEXT) SET (RESTRICT = {}, JOIN = {})",
+            restrict_val, join_val
+        );
+        assert_eq!(
+            pg_and_generic().verified_stmt(&sql),
+            Statement::AlterOperator(AlterOperator {
+                name: ObjectName::from(vec![Ident::new("&&")]),
+                left_type: Some(DataType::Text),
+                right_type: DataType::Text,
+                operation: AlterOperatorOperation::Set {
+                    options: vec![
+                        OperatorOption::Restrict(restrict_ast),
+                        OperatorOption::Join(join_ast),
+                    ],
+                },
+            })
+        );
+    }
+
+    // Test ALTER OPERATOR ... SET with COMMUTATOR and NEGATOR
+    for (operator, commutator, negator) in [("&&", "&&", ">"), ("+", "+", "-"), ("<", "<", ">=")] {
+        let sql = format!(
+            "ALTER OPERATOR {} (INTEGER, INTEGER) SET (COMMUTATOR = {}, NEGATOR = {})",
+            operator, commutator, negator
+        );
+        assert_eq!(
+            pg_and_generic().verified_stmt(&sql),
+            Statement::AlterOperator(AlterOperator {
+                name: ObjectName::from(vec![Ident::new(operator)]),
+                left_type: Some(DataType::Integer(None)),
+                right_type: DataType::Integer(None),
+                operation: AlterOperatorOperation::Set {
+                    options: vec![
+                        OperatorOption::Commutator(ObjectName::from(vec![Ident::new(commutator)])),
+                        OperatorOption::Negator(ObjectName::from(vec![Ident::new(negator)])),
+                    ],
+                },
+            })
+        );
+    }
+
+    // Test ALTER OPERATOR ... SET with HASHES and MERGES (individually and combined)
+    for (operator, options_sql, options_ast) in [
+        ("=", "HASHES", vec![OperatorOption::Hashes]),
+        ("<", "MERGES", vec![OperatorOption::Merges]),
+        (
+            "<=",
+            "HASHES, MERGES",
+            vec![OperatorOption::Hashes, OperatorOption::Merges],
+        ),
+    ] {
+        let sql = format!(
+            "ALTER OPERATOR {} (INTEGER, INTEGER) SET ({})",
+            operator, options_sql
+        );
+        assert_eq!(
+            pg_and_generic().verified_stmt(&sql),
+            Statement::AlterOperator(AlterOperator {
+                name: ObjectName::from(vec![Ident::new(operator)]),
+                left_type: Some(DataType::Integer(None)),
+                right_type: DataType::Integer(None),
+                operation: AlterOperatorOperation::Set {
+                    options: options_ast
+                },
+            })
+        );
+    }
+
+    // Test ALTER OPERATOR ... SET with multiple options combined
+    let sql =
+        "ALTER OPERATOR + (INTEGER, INTEGER) SET (COMMUTATOR = +, NEGATOR = -, HASHES, MERGES)";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperator(AlterOperator {
+            name: ObjectName::from(vec![Ident::new("+")]),
+            left_type: Some(DataType::Integer(None)),
+            right_type: DataType::Integer(None),
+            operation: AlterOperatorOperation::Set {
+                options: vec![
+                    OperatorOption::Commutator(ObjectName::from(vec![Ident::new("+")])),
+                    OperatorOption::Negator(ObjectName::from(vec![Ident::new("-")])),
+                    OperatorOption::Hashes,
+                    OperatorOption::Merges,
+                ],
+            },
+        })
+    );
+}
+
+#[test]
+fn parse_alter_operator_family() {
+    // Test ALTER OPERATOR FAMILY ... ADD OPERATOR
+    let sql = "ALTER OPERATOR FAMILY integer_ops USING btree ADD OPERATOR 1 < (INT4, INT2)";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("integer_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::Add {
+                items: vec![OperatorFamilyItem::Operator {
+                    strategy_number: 1,
+                    operator_name: ObjectName::from(vec![Ident::new("<")]),
+                    op_types: vec![DataType::Int4(None), DataType::Int2(None)],
+                    purpose: None,
+                }],
+            },
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... ADD OPERATOR with FOR SEARCH
+    let sql =
+        "ALTER OPERATOR FAMILY text_ops USING btree ADD OPERATOR 1 @@ (TEXT, TEXT) FOR SEARCH";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("text_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::Add {
+                items: vec![OperatorFamilyItem::Operator {
+                    strategy_number: 1,
+                    operator_name: ObjectName::from(vec![Ident::new("@@")]),
+                    op_types: vec![DataType::Text, DataType::Text],
+                    purpose: Some(OperatorPurpose::ForSearch),
+                }],
+            },
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... ADD FUNCTION
+    let sql = "ALTER OPERATOR FAMILY integer_ops USING btree ADD FUNCTION 1 btint42cmp(INT4, INT2)";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("integer_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::Add {
+                items: vec![OperatorFamilyItem::Function {
+                    support_number: 1,
+                    op_types: None,
+                    function_name: ObjectName::from(vec![Ident::new("btint42cmp")]),
+                    argument_types: vec![DataType::Int4(None), DataType::Int2(None)],
+                }],
+            },
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... DROP OPERATOR
+    let sql = "ALTER OPERATOR FAMILY integer_ops USING btree DROP OPERATOR 1 (INT4, INT2)";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("integer_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::Drop {
+                items: vec![OperatorFamilyDropItem::Operator {
+                    strategy_number: 1,
+                    op_types: vec![DataType::Int4(None), DataType::Int2(None)],
+                }],
+            },
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... DROP FUNCTION
+    let sql = "ALTER OPERATOR FAMILY integer_ops USING btree DROP FUNCTION 1 (INT4, INT2)";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("integer_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::Drop {
+                items: vec![OperatorFamilyDropItem::Function {
+                    support_number: 1,
+                    op_types: vec![DataType::Int4(None), DataType::Int2(None)],
+                }],
+            },
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... RENAME TO
+    let sql = "ALTER OPERATOR FAMILY old_ops USING btree RENAME TO new_ops";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("old_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::RenameTo {
+                new_name: ObjectName::from(vec![Ident::new("new_ops")]),
+            },
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... OWNER TO
+    let sql = "ALTER OPERATOR FAMILY my_ops USING btree OWNER TO joe";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("my_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::OwnerTo(Owner::Ident(Ident::new("joe"))),
+        })
+    );
+
+    // Test ALTER OPERATOR FAMILY ... SET SCHEMA
+    let sql = "ALTER OPERATOR FAMILY my_ops USING btree SET SCHEMA new_schema";
+    assert_eq!(
+        pg_and_generic().verified_stmt(sql),
+        Statement::AlterOperatorFamily(AlterOperatorFamily {
+            name: ObjectName::from(vec![Ident::new("my_ops")]),
+            using: Ident::new("btree"),
+            operation: AlterOperatorFamilyOperation::SetSchema {
+                schema_name: ObjectName::from(vec![Ident::new("new_schema")]),
+            },
+        })
+    );
+
+    // Test error cases
+    // Missing USING clause
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops ADD OPERATOR 1 < (INT4, INT2)")
+        .is_err());
+
+    // Invalid operation
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree INVALID_OPERATION")
+        .is_err());
+
+    // Missing operator name in ADD OPERATOR
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 (INT4, INT2)"
+        )
+        .is_err());
+
+    // Missing function name in ADD FUNCTION
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 (INT4, INT2)"
+        )
+        .is_err());
+
+    // Missing parentheses in DROP OPERATOR
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree DROP OPERATOR 1 INT4, INT2")
+        .is_err());
+
+    // Invalid operator name (empty)
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1  (INT4, INT2)"
+        )
+        .is_err());
+
+    // Invalid operator name (special characters)
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 @#$ (INT4, INT2)"
+        )
+        .is_err());
+
+    // Negative strategy number
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR -1 < (INT4, INT2)"
+        )
+        .is_err());
+
+    // Non-integer strategy number
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1.5 < (INT4, INT2)"
+        )
+        .is_err());
+
+    // Missing closing parenthesis in operator types
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2"
+        )
+        .is_err());
+
+    // Missing opening parenthesis in operator types
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < INT4, INT2)"
+        )
+        .is_err());
+
+    // Empty operator types
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < ()")
+        .is_err());
+
+    // Invalid data type (using punctuation)
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (@#$%, INT2)"
+        )
+        .is_err());
+
+    // Incomplete FOR clause
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) FOR"
+        )
+        .is_err());
+
+    // Invalid FOR clause keyword
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) FOR INVALID"
+        )
+        .is_err());
+
+    // FOR ORDER BY without sort family
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) FOR ORDER BY"
+        )
+        .is_err());
+
+    // Missing function name in ADD FUNCTION
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 (INT4, INT2)"
+        )
+        .is_err());
+
+    // Invalid function name
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 123invalid(INT4, INT2)"
+        )
+        .is_err());
+
+    // Negative support number
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION -1 func(INT4, INT2)"
+        )
+        .is_err());
+
+    // Non-integer support number
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1.5 func(INT4, INT2)"
+        )
+        .is_err());
+
+    // Missing closing parenthesis in function operator types
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 (INT4, INT2 func()"
+        )
+        .is_err());
+
+    // Missing closing parenthesis in function arguments
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 func(INT4, INT2"
+        )
+        .is_err());
+
+    // Invalid data type in function arguments
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 func(@#$%, INT2)"
+        )
+        .is_err());
+
+    // DROP OPERATOR with FOR clause (not allowed)
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree DROP OPERATOR 1 (INT4, INT2) FOR SEARCH"
+        )
+        .is_err());
+
+    // DROP FUNCTION with function arguments (not allowed)
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree DROP FUNCTION 1 (INT4, INT2) func(INT4)"
+        )
+        .is_err());
+
+    // Multiple ADD items with error in middle
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2), INVALID_ITEM"
+        )
+        .is_err());
+
+    // Multiple DROP items with error in middle
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree DROP OPERATOR 1 (INT4, INT2), INVALID_ITEM"
+        )
+        .is_err());
+
+    // RENAME TO with invalid new name
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree RENAME TO 123invalid")
+        .is_err());
+
+    // OWNER TO with invalid owner
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree OWNER TO 123invalid")
+        .is_err());
+
+    // SET SCHEMA with invalid schema name
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree SET SCHEMA 123invalid")
+        .is_err());
+
+    // Schema-qualified operator family name with invalid schema
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY 123invalid.my_ops USING btree ADD OPERATOR 1 < (INT4, INT2)"
+        )
+        .is_err());
+
+    // Missing operator family name
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY USING btree ADD OPERATOR 1 < (INT4, INT2)")
+        .is_err());
+
+    // Extra tokens at end
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) EXTRA"
+        )
+        .is_err());
+
+    // Incomplete statement
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD")
+        .is_err());
+
+    // Very long numbers
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 999999999999999999999 < (INT4, INT2)")
+        .is_err());
+
+    // Multiple FOR clauses
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) FOR SEARCH FOR ORDER BY sort_family")
+        .is_err());
+
+    // FOR SEARCH with extra tokens
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) FOR SEARCH EXTRA")
+        .is_err());
+
+    // FOR ORDER BY with invalid sort family
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD OPERATOR 1 < (INT4, INT2) FOR ORDER BY 123invalid")
+        .is_err());
+
+    // Function with empty operator types but missing function args parens
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 () func")
+        .is_err());
+
+    // Function with mismatched parentheses
+    assert!(pg()
+        .parse_sql_statements(
+            "ALTER OPERATOR FAMILY my_ops USING btree ADD FUNCTION 1 (INT4 func(INT2"
+        )
+        .is_err());
+
+    // DROP with empty types
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree DROP OPERATOR 1 ()")
+        .is_err());
+
+    // DROP FUNCTION with empty types
+    assert!(pg()
+        .parse_sql_statements("ALTER OPERATOR FAMILY my_ops USING btree DROP FUNCTION 1 ()")
+        .is_err());
+}
+
 #[test]
 fn parse_drop_operator_family() {
    for if_exists in [true, false] {
--- a/tests/sqlparser_snowflake.rs
+++ b/tests/sqlparser_snowflake.rs
@ -4635,3 +4635,12 @@ fn test_alter_dynamic_table() {
    snowflake().verified_stmt("ALTER DYNAMIC TABLE my_dyn_table SUSPEND");
    snowflake().verified_stmt("ALTER DYNAMIC TABLE my_dyn_table RESUME");
 }
+
+#[test]
+fn test_alter_external_table() {
+    snowflake().verified_stmt("ALTER EXTERNAL TABLE some_table REFRESH");
+    snowflake().verified_stmt("ALTER EXTERNAL TABLE some_table REFRESH 'year=2025/month=12/'");
+    snowflake().verified_stmt("ALTER EXTERNAL TABLE IF EXISTS some_table REFRESH");
+    snowflake()
+        .verified_stmt("ALTER EXTERNAL TABLE IF EXISTS some_table REFRESH 'year=2025/month=12/'");
+}
Author	SHA1	Message	Date
Andriy Romanov	355a3bfd90	Support parsing parenthesized wildcard `(*)` (#2123 ) Some checks failed Rust / codestyle (push) Has been cancelled Details Rust / lint (push) Has been cancelled Details Rust / benchmark-lint (push) Has been cancelled Details Rust / compile (push) Has been cancelled Details Rust / docs (push) Has been cancelled Details Rust / compile-no-std (push) Has been cancelled Details Rust / test (beta) (push) Has been cancelled Details Rust / test (nightly) (push) Has been cancelled Details Rust / test (stable) (push) Has been cancelled Details license / Release Audit Tool (RAT) (push) Has been cancelled Details	2025-12-19 04:09:33 +00:00
jnlt3	39418cfebb	PostgreSQL Tokenization: Fix unexpected characters after question mark being silently ignored (#2129 ) Some checks are pending license / Release Audit Tool (RAT) (push) Waiting to run Details Rust / codestyle (push) Waiting to run Details Rust / lint (push) Waiting to run Details Rust / benchmark-lint (push) Waiting to run Details Rust / compile (push) Waiting to run Details Rust / docs (push) Waiting to run Details Rust / compile-no-std (push) Waiting to run Details Rust / test (beta) (push) Waiting to run Details Rust / test (nightly) (push) Waiting to run Details Rust / test (stable) (push) Waiting to run Details	2025-12-18 12:06:55 +00:00
Luca Cappelletti	d78dbc97a1	Added support for `ALTER OPERATOR FAMILY` syntax (#2125 ) Some checks are pending license / Release Audit Tool (RAT) (push) Waiting to run Details Rust / codestyle (push) Waiting to run Details Rust / lint (push) Waiting to run Details Rust / benchmark-lint (push) Waiting to run Details Rust / compile (push) Waiting to run Details Rust / docs (push) Waiting to run Details Rust / compile-no-std (push) Waiting to run Details Rust / test (beta) (push) Waiting to run Details Rust / test (nightly) (push) Waiting to run Details Rust / test (stable) (push) Waiting to run Details	2025-12-18 04:34:48 +00:00
xitep	f84887d004	Oracle: Support for quote delimited strings (#2130 ) Some checks failed license / Release Audit Tool (RAT) (push) Has been cancelled Details Rust / codestyle (push) Has been cancelled Details Rust / lint (push) Has been cancelled Details Rust / benchmark-lint (push) Has been cancelled Details Rust / compile (push) Has been cancelled Details Rust / docs (push) Has been cancelled Details Rust / compile-no-std (push) Has been cancelled Details Rust / test (beta) (push) Has been cancelled Details Rust / test (nightly) (push) Has been cancelled Details Rust / test (stable) (push) Has been cancelled Details	2025-12-16 18:04:11 +00:00
Denis Goncharenko	cdeed32294	PostgreSQL: Support schema-qualified operator classes in CREATE INDEX (#2131 ) Some checks are pending license / Release Audit Tool (RAT) (push) Waiting to run Details Rust / codestyle (push) Waiting to run Details Rust / lint (push) Waiting to run Details Rust / benchmark-lint (push) Waiting to run Details Rust / compile (push) Waiting to run Details Rust / docs (push) Waiting to run Details Rust / compile-no-std (push) Waiting to run Details Rust / test (beta) (push) Waiting to run Details Rust / test (nightly) (push) Waiting to run Details Rust / test (stable) (push) Waiting to run Details	2025-12-16 12:07:11 +00:00
xitep	9b8a2d1e22	Extract source comments (#2107 ) Co-authored-by: Ifeanyi Ubah <ify1992@yahoo.com>	2025-12-16 11:30:30 +00:00
Yoav Cohen	1b842d3b6a	MSSQL: Parse IF/ELSE without semicolon delimiters (#2128 ) Some checks failed license / Release Audit Tool (RAT) (push) Has been cancelled Details Rust / codestyle (push) Has been cancelled Details Rust / lint (push) Has been cancelled Details Rust / benchmark-lint (push) Has been cancelled Details Rust / compile (push) Has been cancelled Details Rust / docs (push) Has been cancelled Details Rust / compile-no-std (push) Has been cancelled Details Rust / test (beta) (push) Has been cancelled Details Rust / test (nightly) (push) Has been cancelled Details Rust / test (stable) (push) Has been cancelled Details	2025-12-10 12:04:22 +00:00
Yoav Cohen	0b1e0c35d9	MSSQL: Add support for parenthesized stored procedure name in EXEC (#2126 )	2025-12-10 11:53:22 +00:00
Andriy Romanov	048bc8f09d	Added alter external table support for snowflake (#2122 )	2025-12-10 11:51:44 +00:00
xitep	adbfc46177	[Oracle] Lower StringConcat precedence (#2115 )	2025-12-10 11:50:26 +00:00
xitep	ca2d333dff	Oracle: Support for MERGE predicates (#2101 ) Some checks failed license / Release Audit Tool (RAT) (push) Has been cancelled Details Rust / lint (push) Has been cancelled Details Rust / benchmark-lint (push) Has been cancelled Details Rust / codestyle (push) Has been cancelled Details Rust / compile (push) Has been cancelled Details Rust / docs (push) Has been cancelled Details Rust / compile-no-std (push) Has been cancelled Details Rust / test (beta) (push) Has been cancelled Details Rust / test (nightly) (push) Has been cancelled Details Rust / test (stable) (push) Has been cancelled Details Co-authored-by: Ifeanyi Ubah <ify1992@yahoo.com>	2025-12-06 07:59:50 +00:00
Luca Cappelletti	326f111808	Added support for `ALTER OPERATOR` syntax (#2114 ) Some checks failed license / Release Audit Tool (RAT) (push) Has been cancelled Details Rust / codestyle (push) Has been cancelled Details Rust / lint (push) Has been cancelled Details Rust / benchmark-lint (push) Has been cancelled Details Rust / compile (push) Has been cancelled Details Rust / docs (push) Has been cancelled Details Rust / compile-no-std (push) Has been cancelled Details Rust / test (beta) (push) Has been cancelled Details Rust / test (nightly) (push) Has been cancelled Details Rust / test (stable) (push) Has been cancelled Details	2025-12-04 13:17:31 +00:00
Martin Grigorov	effaac5c39	fix: Set the current folder as a "primary" for the `find` command (#2120 ) Some checks are pending license / Release Audit Tool (RAT) (push) Waiting to run Details Rust / codestyle (push) Waiting to run Details Rust / lint (push) Waiting to run Details Rust / benchmark-lint (push) Waiting to run Details Rust / compile (push) Waiting to run Details Rust / docs (push) Waiting to run Details Rust / compile-no-std (push) Waiting to run Details Rust / test (beta) (push) Waiting to run Details Rust / test (nightly) (push) Waiting to run Details Rust / test (stable) (push) Waiting to run Details	2025-12-03 20:01:51 +00:00
Andriy Romanov	5a3b63bf41	Fixing location for extrenal tables (#2108 ) Some checks are pending license / Release Audit Tool (RAT) (push) Waiting to run Details Rust / codestyle (push) Waiting to run Details Rust / lint (push) Waiting to run Details Rust / benchmark-lint (push) Waiting to run Details Rust / compile (push) Waiting to run Details Rust / test (beta) (push) Waiting to run Details Rust / docs (push) Waiting to run Details Rust / compile-no-std (push) Waiting to run Details Rust / test (nightly) (push) Waiting to run Details Rust / test (stable) (push) Waiting to run Details	2025-12-03 05:14:34 +00:00