diff --git a/vortex-array/src/arrays/extension/vtable/rules.rs b/vortex-array/src/arrays/extension/vtable/rules.rs
index 0ff04f6cd42..92a34c76cab 100644
--- a/vortex-array/src/arrays/extension/vtable/rules.rs
+++ b/vortex-array/src/arrays/extension/vtable/rules.rs
@@ -73,7 +73,7 @@ mod tests {
     use crate::expr::Operator;
     use crate::optimizer::ArrayOptimizer;
 
-    #[derive(Clone, Debug, Default)]
+    #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
     struct TestExt;
     impl ExtDTypeVTable for TestExt {
         type Metadata = EmptyMetadata;
@@ -82,7 +82,11 @@ mod tests {
             ExtID::new_ref("test_ext")
         }
 
-        fn validate(&self, _options: &Self::Metadata, _storage_dtype: &DType) -> VortexResult<()> {
+        fn validate_dtype(
+            &self,
+            _options: &Self::Metadata,
+            _storage_dtype: &DType,
+        ) -> VortexResult<()> {
             Ok(())
         }
     }
@@ -153,7 +157,7 @@ mod tests {
 
     #[test]
     fn test_scalar_fn_no_pushdown_different_ext_types() {
-        #[derive(Clone, Debug, Default)]
+        #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
         struct TestExt2;
         impl ExtDTypeVTable for TestExt2 {
             type Metadata = EmptyMetadata;
@@ -162,7 +166,7 @@ mod tests {
                 ExtID::new_ref("test_ext_2")
             }
 
-            fn validate(
+            fn validate_dtype(
                 &self,
                 _options: &Self::Metadata,
                 _storage_dtype: &DType,
diff --git a/vortex-dtype/src/datetime/date.rs b/vortex-dtype/src/datetime/date.rs
index 66738a2cbb4..96040186f10 100644
--- a/vortex-dtype/src/datetime/date.rs
+++ b/vortex-dtype/src/datetime/date.rs
@@ -15,7 +15,7 @@ use crate::extension::ExtDTypeVTable;
 use crate::extension::ExtID;
 
 /// Date DType.
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
 pub struct Date;
 
 impl Date {
@@ -54,7 +54,7 @@ impl ExtDTypeVTable for Date {
         TimeUnit::try_from(tag)
     }
 
-    fn validate(&self, metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()> {
+    fn validate_dtype(&self, metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()> {
         let ptype = date_ptype(metadata)
             .ok_or_else(|| vortex_err!("Date type does not support time unit {}", metadata))?;
 
diff --git a/vortex-dtype/src/datetime/time.rs b/vortex-dtype/src/datetime/time.rs
index f1f45014058..b654a30b4fd 100644
--- a/vortex-dtype/src/datetime/time.rs
+++ b/vortex-dtype/src/datetime/time.rs
@@ -15,7 +15,7 @@ use crate::extension::ExtDTypeVTable;
 use crate::extension::ExtID;
 
 /// Time DType.
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
 pub struct Time;
 
 impl Time {
@@ -50,7 +50,7 @@ impl ExtDTypeVTable for Time {
         TimeUnit::try_from(tag)
     }
 
-    fn validate(&self, metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()> {
+    fn validate_dtype(&self, metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()> {
         let ptype = time_ptype(metadata)
             .ok_or_else(|| vortex_err!("Time type does not support time unit {}", metadata))?;
 
diff --git a/vortex-dtype/src/datetime/timestamp.rs b/vortex-dtype/src/datetime/timestamp.rs
index 56bbdcdd094..d86d62ffc11 100644
--- a/vortex-dtype/src/datetime/timestamp.rs
+++ b/vortex-dtype/src/datetime/timestamp.rs
@@ -22,11 +22,11 @@ use crate::extension::ExtDTypeVTable;
 use crate::extension::ExtID;
 
 /// Timestamp DType.
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
 pub struct Timestamp;
 
 impl Timestamp {
-    /// Creates a new Timestamp extension dtype with the given time unit and nullability.
+    /// Creates a new Timestamp extension =dtype with the given time unit and nullability.
     pub fn new(time_unit: TimeUnit, nullability: Nullability) -> ExtDType<Self> {
         Self::new_with_tz(time_unit, None, nullability)
     }
@@ -120,7 +120,11 @@ impl ExtDTypeVTable for Timestamp {
         })
     }
 
-    fn validate(&self, _metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()> {
+    fn validate_dtype(
+        &self,
+        _metadata: &Self::Metadata,
+        storage_dtype: &DType,
+    ) -> VortexResult<()> {
         vortex_ensure!(
             matches!(storage_dtype, DType::Primitive(PType::I64, _)),
             "Timestamp storage dtype must be i64"
diff --git a/vortex-dtype/src/extension/mod.rs b/vortex-dtype/src/extension/mod.rs
index d287120aa04..d6d955346c5 100644
--- a/vortex-dtype/src/extension/mod.rs
+++ b/vortex-dtype/src/extension/mod.rs
@@ -47,7 +47,7 @@ impl<V: ExtDTypeVTable> ExtDType<V> {
         metadata: V::Metadata,
         storage_dtype: DType,
     ) -> VortexResult<Self> {
-        vtable.validate(&metadata, &storage_dtype)?;
+        vtable.validate_dtype(&metadata, &storage_dtype)?;
         Ok(Self(Arc::new(ExtDTypeAdapter::<V> {
             vtable,
             metadata,
diff --git a/vortex-dtype/src/extension/vtable.rs b/vortex-dtype/src/extension/vtable.rs
index b650c187c5e..2832c60c3a5 100644
--- a/vortex-dtype/src/extension/vtable.rs
+++ b/vortex-dtype/src/extension/vtable.rs
@@ -14,7 +14,7 @@ use crate::ExtID;
 use crate::extension::ExtDTypeRef;
 
 /// The public API for defining new extension DTypes.
-pub trait ExtDTypeVTable: 'static + Sized + Send + Sync + Clone + Debug {
+pub trait ExtDTypeVTable: 'static + Sized + Send + Sync + Clone + Debug + Eq + Hash {
     /// Associated type containing the deserialized metadata for this extension type
     type Metadata: 'static + Send + Sync + Clone + Debug + Display + Eq + Hash;
 
@@ -40,23 +40,20 @@ pub trait ExtDTypeVTable: 'static + Sized + Send + Sync + Clone + Debug {
     }
 
     /// Validate that the given storage type is compatible with this extension type.
-    fn validate(&self, metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()>;
+    fn validate_dtype(&self, metadata: &Self::Metadata, storage_dtype: &DType) -> VortexResult<()>;
 }
 
 /// A dynamic vtable for extension types, used for type-erased deserialization.
 // TODO(ngates): consider renaming this to ExtDTypePlugin or similar?
-pub trait DynVTable: 'static + Send + Sync + Debug {
+pub trait DynExtDTypeVTable: 'static + Send + Sync + Debug {
     /// Returns the ID for this extension type.
     fn id(&self) -> ExtID;
 
     /// Deserialize an extension type from serialized metadata.
     fn deserialize(&self, data: &[u8], storage_dtype: DType) -> VortexResult<ExtDTypeRef>;
-
-    /// Clones this vtable into a boxed trait object.
-    fn clone_box(&self) -> Box<dyn DynVTable>;
 }
 
-impl<V: ExtDTypeVTable> DynVTable for V {
+impl<V: ExtDTypeVTable> DynExtDTypeVTable for V {
     fn id(&self) -> ExtID {
         ExtDTypeVTable::id(self)
     }
@@ -65,10 +62,6 @@ impl<V: ExtDTypeVTable> DynVTable for V {
         let metadata = ExtDTypeVTable::deserialize(self, data)?;
         Ok(ExtDType::try_with_vtable(self.clone(), metadata, storage_dtype)?.erased())
     }
-
-    fn clone_box(&self) -> Box<dyn DynVTable> {
-        Box::new(self.clone())
-    }
 }
 
 /// An empty metadata struct for extension dtypes that do not require any metadata.
diff --git a/vortex-dtype/src/session.rs b/vortex-dtype/src/session.rs
index 5f8afcd780e..d17fa1c94b5 100644
--- a/vortex-dtype/src/session.rs
+++ b/vortex-dtype/src/session.rs
@@ -12,11 +12,11 @@ use vortex_session::registry::Registry;
 use crate::datetime::Date;
 use crate::datetime::Time;
 use crate::datetime::Timestamp;
-use crate::extension::DynVTable;
+use crate::extension::DynExtDTypeVTable;
 use crate::extension::ExtDTypeVTable;
 
 /// Registry for extension dtypes.
-pub type ExtDTypeRegistry = Registry<Arc<dyn DynVTable>>;
+pub type ExtDTypeRegistry = Registry<Arc<dyn DynExtDTypeVTable>>;
 
 /// Session for managing extension dtypes.
 #[derive(Debug)]
@@ -43,7 +43,7 @@ impl DTypeSession {
     /// Register an extension DType with the Vortex session.
     pub fn register<V: ExtDTypeVTable>(&self, vtable: V) {
         self.registry
-            .register(vtable.id(), Arc::new(vtable) as Arc<dyn DynVTable>);
+            .register(vtable.id(), Arc::new(vtable) as Arc<dyn DynExtDTypeVTable>);
     }
 
     /// Return the registry of extension dtypes.
diff --git a/vortex-duckdb/src/convert/dtype.rs b/vortex-duckdb/src/convert/dtype.rs
index 6c468811f54..d6481cafc70 100644
--- a/vortex-duckdb/src/convert/dtype.rs
+++ b/vortex-duckdb/src/convert/dtype.rs
@@ -567,7 +567,7 @@ mod tests {
         use vortex::dtype::ExtID;
         use vortex::dtype::PType;
 
-        #[derive(Clone, Debug, Default)]
+        #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
         struct TestExt;
         impl ExtDTypeVTable for TestExt {
             type Metadata = EmptyMetadata;
@@ -576,7 +576,7 @@ mod tests {
                 ExtID::new_ref("unknown.extension")
             }
 
-            fn validate(
+            fn validate_dtype(
                 &self,
                 _options: &Self::Metadata,
                 _storage_dtype: &DType,
diff --git a/vortex-scalar/src/arrow/tests.rs b/vortex-scalar/src/arrow/tests.rs
index e4eb451ac42..5b1d0390e00 100644
--- a/vortex-scalar/src/arrow/tests.rs
+++ b/vortex-scalar/src/arrow/tests.rs
@@ -262,7 +262,7 @@ fn test_list_scalar_to_arrow_todo() {
 fn test_non_temporal_extension_to_arrow_todo() {
     use vortex_dtype::ExtID;
 
-    #[derive(Debug, Clone, Default)]
+    #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
     struct SomeExt;
     impl ExtDTypeVTable for SomeExt {
         type Metadata = String;
@@ -279,7 +279,11 @@ fn test_non_temporal_extension_to_arrow_todo() {
             vortex_bail!("not implemented")
         }
 
-        fn validate(&self, _options: &Self::Metadata, _storage_dtype: &DType) -> VortexResult<()> {
+        fn validate_dtype(
+            &self,
+            _options: &Self::Metadata,
+            _storage_dtype: &DType,
+        ) -> VortexResult<()> {
             Ok(())
         }
     }
diff --git a/vortex-scalar/src/extension.rs b/vortex-scalar/src/extension.rs
index d64ef9f22c4..5983b9a13ab 100644
--- a/vortex-scalar/src/extension.rs
+++ b/vortex-scalar/src/extension.rs
@@ -167,7 +167,7 @@ mod tests {
     use crate::Scalar;
     use crate::ScalarValue;
 
-    #[derive(Debug, Clone, Default)]
+    #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
     struct TestExt;
     impl ExtDTypeVTable for TestExt {
         type Metadata = EmptyMetadata;
@@ -176,7 +176,11 @@ mod tests {
             ExtID::new_ref("test_ext")
         }
 
-        fn validate(&self, _options: &Self::Metadata, _storage_dtype: &DType) -> VortexResult<()> {
+        fn validate_dtype(
+            &self,
+            _options: &Self::Metadata,
+            _storage_dtype: &DType,
+        ) -> VortexResult<()> {
             Ok(())
         }
     }
@@ -234,7 +238,7 @@ mod tests {
 
     #[test]
     fn test_ext_scalar_partial_ord_different_types() {
-        #[derive(Clone, Debug, Default)]
+        #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
         struct TestExt2;
         impl ExtDTypeVTable for TestExt2 {
             type Metadata = EmptyMetadata;
@@ -243,7 +247,7 @@ mod tests {
                 ExtID::new_ref("test_ext_2")
             }
 
-            fn validate(
+            fn validate_dtype(
                 &self,
                 _options: &Self::Metadata,
                 _storage_dtype: &DType,
@@ -413,7 +417,7 @@ mod tests {
 
     #[test]
     fn test_ext_scalar_with_metadata() {
-        #[derive(Clone, Debug, Default)]
+        #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
         struct TestExtMetadata;
         impl ExtDTypeVTable for TestExtMetadata {
             type Metadata = usize;
@@ -422,7 +426,7 @@ mod tests {
                 ExtID::new_ref("test_ext_metadata")
             }
 
-            fn validate(
+            fn validate_dtype(
                 &self,
                 _options: &Self::Metadata,
                 _storage_dtype: &DType,
diff --git a/vortex-scalar/src/tests/casting.rs b/vortex-scalar/src/tests/casting.rs
index cb05f1fcd8a..3d38699f426 100644
--- a/vortex-scalar/src/tests/casting.rs
+++ b/vortex-scalar/src/tests/casting.rs
@@ -24,7 +24,7 @@ mod tests {
     use crate::Scalar;
     use crate::ScalarValue;
 
-    #[derive(Clone, Debug, Default)]
+    #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
     struct Apples;
     impl ExtDTypeVTable for Apples {
         type Metadata = usize;
@@ -33,7 +33,11 @@ mod tests {
             ExtID::new_ref("apples")
         }
 
-        fn validate(&self, _options: &Self::Metadata, _storage_dtype: &DType) -> VortexResult<()> {
+        fn validate_dtype(
+            &self,
+            _options: &Self::Metadata,
+            _storage_dtype: &DType,
+        ) -> VortexResult<()> {
             Ok(())
         }
     }
@@ -311,7 +315,7 @@ mod tests {
     #[test]
     fn test_extension_dtype_coercion() {
         // Create an extension type with f16 storage
-        #[derive(Debug, Clone, Default)]
+        #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
         struct F16Ext;
         impl ExtDTypeVTable for F16Ext {
             type Metadata = usize;
@@ -320,7 +324,7 @@ mod tests {
                 ExtID::new_ref("f16_ext")
             }
 
-            fn validate(
+            fn validate_dtype(
                 &self,
                 _options: &Self::Metadata,
                 _storage_dtype: &DType,
@@ -356,7 +360,7 @@ mod tests {
     #[test]
     fn test_extension_dtype_nested_struct_coercion() {
         // Create an extension type with struct storage that contains f16 field
-        #[derive(Debug, Clone, Default)]
+        #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
         struct StructExt;
         impl ExtDTypeVTable for StructExt {
             type Metadata = usize;
@@ -365,7 +369,7 @@ mod tests {
                 ExtID::new_ref("struct_ext")
             }
 
-            fn validate(
+            fn validate_dtype(
                 &self,
                 _options: &Self::Metadata,
                 _storage_dtype: &DType,