Introduce LogicalTypeId::Unsupported

Author: mlafeldt

crates/duckdb/src/core/logical_type.rs

@@ -91,6 +91,8 @@ pub enum LogicalTypeId {
     IntegerLiteral = DUCKDB_TYPE_DUCKDB_TYPE_INTEGER_LITERAL,
     /// Time NS
     TimeNs = DUCKDB_TYPE_DUCKDB_TYPE_TIME_NS,
+    /// DuckDB returned a type that this wrapper does not yet recognize
+    Unsupported = u32::MAX,
 }
 
 impl From<u32> for LogicalTypeId {
@@ -137,9 +139,8 @@ impl From<u32> for LogicalTypeId {
             DUCKDB_TYPE_DUCKDB_TYPE_STRING_LITERAL => Self::StringLiteral,
             DUCKDB_TYPE_DUCKDB_TYPE_INTEGER_LITERAL => Self::IntegerLiteral,
             DUCKDB_TYPE_DUCKDB_TYPE_TIME_NS => Self::TimeNs,
-            // Return Invalid for unknown types to handle forward compatibility
-            // when DuckDB adds new types in future versions
-            _ => Self::Invalid,
+            // Unknown / forward compatible types
+            _ => Self::Unsupported,
         }
     }
 }
@@ -285,8 +286,12 @@ impl LogicalTypeHandle {
 
     /// Logical type ID
     pub fn id(&self) -> LogicalTypeId {
-        let duckdb_type_id = unsafe { duckdb_get_type_id(self.ptr) };
-        duckdb_type_id.into()
+        self.raw_id().into()
+    }
+
+    /// Raw logical type id returned by DuckDB C API
+    pub fn raw_id(&self) -> u32 {
+        unsafe { duckdb_get_type_id(self.ptr) }
     }
 
     /// Logical type children num
@@ -412,4 +417,9 @@ mod test {
         let debug_str = format!("{invalid_type:?}");
         assert_eq!(debug_str, "Invalid");
     }
+
+    #[test]
+    fn test_unknown_type() {
+        assert_eq!(LogicalTypeId::from(999_999), LogicalTypeId::Unsupported);
+    }
 }

crates/duckdb/src/vtab/arrow.rs

@@ -259,9 +259,11 @@ pub fn flat_vector_to_arrow_array(
     vector: &mut FlatVector,
     len: usize,
 ) -> Result<Arc<dyn Array>, Box<dyn std::error::Error>> {
-    let type_id = vector.logical_type().id();
+    let raw_type_id = vector.logical_type().raw_id();
+    let type_id = LogicalTypeId::from(raw_type_id);
     match type_id {
-        LogicalTypeId::Invalid => Err("Cannot convert invalid logical type to arrow array".into()),
+        LogicalTypeId::Invalid => Err("Cannot convert invalid logical type returned by DuckDB".into()),
+        LogicalTypeId::Unsupported => Err(format!("Unsupported DuckDB logical type ID {raw_type_id}").into()),
         LogicalTypeId::Integer => {
             let data = vector.as_slice_with_len::<i32>(len);