diff --git a/vortex-array/public-api.lock b/vortex-array/public-api.lock
index 7d122a6f98c..85e3e658c6f 100644
--- a/vortex-array/public-api.lock
+++ b/vortex-array/public-api.lock
@@ -6528,6 +6528,8 @@ impl vortex_array::dtype::datetime::Timestamp
 
 pub fn vortex_array::dtype::datetime::Timestamp::new(time_unit: vortex_array::dtype::datetime::TimeUnit, nullability: vortex_array::dtype::Nullability) -> vortex_array::dtype::extension::ExtDType<Self>
 
+pub fn vortex_array::dtype::datetime::Timestamp::new_with_options(options: vortex_array::dtype::datetime::TimestampOptions, nullability: vortex_array::dtype::Nullability) -> vortex_array::dtype::extension::ExtDType<Self>
+
 pub fn vortex_array::dtype::datetime::Timestamp::new_with_tz(time_unit: vortex_array::dtype::datetime::TimeUnit, timezone: core::option::Option<alloc::sync::Arc<str>>, nullability: vortex_array::dtype::Nullability) -> vortex_array::dtype::extension::ExtDType<Self>
 
 impl core::clone::Clone for vortex_array::dtype::datetime::Timestamp
@@ -6642,10 +6644,28 @@ pub fn vortex_array::dtype::extension::ExtDType<V>::storage_dtype(&self) -> &vor
 
 pub fn vortex_array::dtype::extension::ExtDType<V>::try_with_vtable(vtable: V, metadata: <V as vortex_array::dtype::extension::ExtDTypeVTable>::Metadata, storage_dtype: vortex_array::dtype::DType) -> vortex_error::VortexResult<Self>
 
+pub fn vortex_array::dtype::extension::ExtDType<V>::vtable(&self) -> &V
+
 impl<V: core::clone::Clone + vortex_array::dtype::extension::ExtDTypeVTable> core::clone::Clone for vortex_array::dtype::extension::ExtDType<V>
 
 pub fn vortex_array::dtype::extension::ExtDType<V>::clone(&self) -> vortex_array::dtype::extension::ExtDType<V>
 
+impl<V: core::cmp::Eq + vortex_array::dtype::extension::ExtDTypeVTable> core::cmp::Eq for vortex_array::dtype::extension::ExtDType<V>
+
+impl<V: core::cmp::PartialEq + vortex_array::dtype::extension::ExtDTypeVTable> core::cmp::PartialEq for vortex_array::dtype::extension::ExtDType<V>
+
+pub fn vortex_array::dtype::extension::ExtDType<V>::eq(&self, other: &vortex_array::dtype::extension::ExtDType<V>) -> bool
+
+impl<V: core::fmt::Debug + vortex_array::dtype::extension::ExtDTypeVTable> core::fmt::Debug for vortex_array::dtype::extension::ExtDType<V>
+
+pub fn vortex_array::dtype::extension::ExtDType<V>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result
+
+impl<V: core::hash::Hash + vortex_array::dtype::extension::ExtDTypeVTable> core::hash::Hash for vortex_array::dtype::extension::ExtDType<V>
+
+pub fn vortex_array::dtype::extension::ExtDType<V>::hash<__H: core::hash::Hasher>(&self, state: &mut __H)
+
+impl<V: vortex_array::dtype::extension::ExtDTypeVTable> core::marker::StructuralPartialEq for vortex_array::dtype::extension::ExtDType<V>
+
 pub struct vortex_array::dtype::extension::ExtDTypeMetadata<'a>
 
 impl vortex_array::dtype::extension::ExtDTypeMetadata<'_>
@@ -6690,8 +6710,12 @@ pub fn vortex_array::dtype::extension::ExtDTypeRef::eq_ignore_nullability(&self,
 
 pub fn vortex_array::dtype::extension::ExtDTypeRef::id(&self) -> vortex_array::dtype::extension::ExtID
 
+pub fn vortex_array::dtype::extension::ExtDTypeRef::is_nullable(&self) -> bool
+
 pub fn vortex_array::dtype::extension::ExtDTypeRef::metadata_erased(&self) -> vortex_array::dtype::extension::ExtDTypeMetadata<'_>
 
+pub fn vortex_array::dtype::extension::ExtDTypeRef::nullability(&self) -> vortex_array::dtype::Nullability
+
 pub fn vortex_array::dtype::extension::ExtDTypeRef::storage_dtype(&self) -> &vortex_array::dtype::DType
 
 pub fn vortex_array::dtype::extension::ExtDTypeRef::with_nullability(&self, nullability: vortex_array::dtype::Nullability) -> Self
@@ -7520,10 +7544,28 @@ pub fn vortex_array::dtype::extension::ExtDType<V>::storage_dtype(&self) -> &vor
 
 pub fn vortex_array::dtype::extension::ExtDType<V>::try_with_vtable(vtable: V, metadata: <V as vortex_array::dtype::extension::ExtDTypeVTable>::Metadata, storage_dtype: vortex_array::dtype::DType) -> vortex_error::VortexResult<Self>
 
+pub fn vortex_array::dtype::extension::ExtDType<V>::vtable(&self) -> &V
+
 impl<V: core::clone::Clone + vortex_array::dtype::extension::ExtDTypeVTable> core::clone::Clone for vortex_array::dtype::extension::ExtDType<V>
 
 pub fn vortex_array::dtype::extension::ExtDType<V>::clone(&self) -> vortex_array::dtype::extension::ExtDType<V>
 
+impl<V: core::cmp::Eq + vortex_array::dtype::extension::ExtDTypeVTable> core::cmp::Eq for vortex_array::dtype::extension::ExtDType<V>
+
+impl<V: core::cmp::PartialEq + vortex_array::dtype::extension::ExtDTypeVTable> core::cmp::PartialEq for vortex_array::dtype::extension::ExtDType<V>
+
+pub fn vortex_array::dtype::extension::ExtDType<V>::eq(&self, other: &vortex_array::dtype::extension::ExtDType<V>) -> bool
+
+impl<V: core::fmt::Debug + vortex_array::dtype::extension::ExtDTypeVTable> core::fmt::Debug for vortex_array::dtype::extension::ExtDType<V>
+
+pub fn vortex_array::dtype::extension::ExtDType<V>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result
+
+impl<V: core::hash::Hash + vortex_array::dtype::extension::ExtDTypeVTable> core::hash::Hash for vortex_array::dtype::extension::ExtDType<V>
+
+pub fn vortex_array::dtype::extension::ExtDType<V>::hash<__H: core::hash::Hasher>(&self, state: &mut __H)
+
+impl<V: vortex_array::dtype::extension::ExtDTypeVTable> core::marker::StructuralPartialEq for vortex_array::dtype::extension::ExtDType<V>
+
 pub struct vortex_array::dtype::ExtDTypeRef(_)
 
 impl vortex_array::dtype::extension::ExtDTypeRef
@@ -7544,8 +7586,12 @@ pub fn vortex_array::dtype::extension::ExtDTypeRef::eq_ignore_nullability(&self,
 
 pub fn vortex_array::dtype::extension::ExtDTypeRef::id(&self) -> vortex_array::dtype::extension::ExtID
 
+pub fn vortex_array::dtype::extension::ExtDTypeRef::is_nullable(&self) -> bool
+
 pub fn vortex_array::dtype::extension::ExtDTypeRef::metadata_erased(&self) -> vortex_array::dtype::extension::ExtDTypeMetadata<'_>
 
+pub fn vortex_array::dtype::extension::ExtDTypeRef::nullability(&self) -> vortex_array::dtype::Nullability
+
 pub fn vortex_array::dtype::extension::ExtDTypeRef::storage_dtype(&self) -> &vortex_array::dtype::DType
 
 pub fn vortex_array::dtype::extension::ExtDTypeRef::with_nullability(&self, nullability: vortex_array::dtype::Nullability) -> Self
diff --git a/vortex-array/src/dtype/datetime/timestamp.rs b/vortex-array/src/dtype/datetime/timestamp.rs
index d5e4b261006..c7069032fee 100644
--- a/vortex-array/src/dtype/datetime/timestamp.rs
+++ b/vortex-array/src/dtype/datetime/timestamp.rs
@@ -46,6 +46,12 @@ impl Timestamp {
         )
         .vortex_expect("failed to create timestamp dtype")
     }
+
+    /// Creates a new `Timestamp` extension dtype with the given options and nullability.
+    pub fn new_with_options(options: TimestampOptions, nullability: Nullability) -> ExtDType<Self> {
+        ExtDType::try_new(options, DType::Primitive(PType::I64, nullability))
+            .vortex_expect("failed to create timestamp dtype")
+    }
 }
 
 /// Options for the Timestamp DType.
diff --git a/vortex-array/src/dtype/extension/mod.rs b/vortex-array/src/dtype/extension/mod.rs
index 27c082e47ca..a6c3a494fae 100644
--- a/vortex-array/src/dtype/extension/mod.rs
+++ b/vortex-array/src/dtype/extension/mod.rs
@@ -29,7 +29,7 @@ use crate::dtype::Nullability;
 pub type ExtID = ArcRef<str>;
 
 /// An extension data type.
-#[derive(Clone)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ExtDType<V: ExtDTypeVTable>(Arc<ExtDTypeAdapter<V>>);
 
 // Convenience impls for zero-sized VTables
@@ -60,6 +60,11 @@ impl<V: ExtDTypeVTable> ExtDType<V> {
         self.0.id()
     }
 
+    /// Returns the vtable of the extension type.
+    pub fn vtable(&self) -> &V {
+        &self.0.vtable
+    }
+
     /// Returns the metadata of the extension type.
     pub fn metadata(&self) -> &V::Metadata {
         &self.0.metadata
@@ -135,9 +140,20 @@ impl ExtDTypeRef {
         self.0.storage_dtype()
     }
 
+    /// Returns the nullability of the storage dtype.
+    pub fn nullability(&self) -> Nullability {
+        // The nullability of the extension type must always be the same as the storage type.
+        self.storage_dtype().nullability()
+    }
+
+    /// Returns true if the storage dtype is nullable.
+    pub fn is_nullable(&self) -> bool {
+        self.nullability().is_nullable()
+    }
+
     /// Returns a new ExtDTypeRef with the given nullability.
     pub fn with_nullability(&self, nullability: Nullability) -> Self {
-        if self.storage_dtype().nullability() == nullability {
+        if self.nullability() == nullability {
             self.clone()
         } else {
             self.0.with_nullability(nullability)
@@ -211,7 +227,7 @@ impl ExtDTypeRef {
 
 /// Wrapper for type-erased extension dtype metadata.
 pub struct ExtDTypeMetadata<'a> {
-    pub(super) ext_dtype: &'a ExtDTypeRef,
+    ext_dtype: &'a ExtDTypeRef,
 }
 
 impl ExtDTypeMetadata<'_> {
@@ -262,6 +278,7 @@ trait ExtDTypeImpl: 'static + Send + Sync + private::Sealed {
     fn with_nullability(&self, nullability: Nullability) -> ExtDTypeRef;
 }
 
+#[derive(Debug, PartialEq, Eq, Hash)]
 struct ExtDTypeAdapter<V: ExtDTypeVTable> {
     vtable: V,
     metadata: V::Metadata,