From 53c146a5d3ce866cef6bb8e5828899bd393a5a6c Mon Sep 17 00:00:00 2001
From: Joe Isaacs <joe.isaacs@live.co.uk>
Date: Fri, 23 Jan 2026 19:19:39 +0000
Subject: [PATCH 1/2] feat[cuda]: to_host canonical

Signed-off-by: Joe Isaacs <joe.isaacs@live.co.uk>
---
 vortex-cuda/src/canonical.rs | 64 ++++++++++++++++++++++++++++++++++++
 vortex-cuda/src/lib.rs       |  2 ++
 2 files changed, 66 insertions(+)
 create mode 100644 vortex-cuda/src/canonical.rs

diff --git a/vortex-cuda/src/canonical.rs b/vortex-cuda/src/canonical.rs
new file mode 100644
index 00000000000..4dc417f1165
--- /dev/null
+++ b/vortex-cuda/src/canonical.rs
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+use async_trait::async_trait;
+use vortex_array::Canonical;
+use vortex_array::arrays::BoolArray;
+use vortex_array::arrays::BoolArrayParts;
+use vortex_array::arrays::DecimalArray;
+use vortex_array::arrays::DecimalArrayParts;
+use vortex_array::arrays::PrimitiveArray;
+use vortex_array::arrays::PrimitiveArrayParts;
+use vortex_array::buffer::BufferHandle;
+use vortex_error::VortexResult;
+
+/// Move all canonical data from to_host from device.
+#[async_trait]
+pub trait CanonicalCudaExt {
+    async fn to_host(self) -> VortexResult<Self>;
+}
+
+impl CanonicalCudaExt for Canonical {
+    async fn to_host(self) -> VortexResult<Self> {
+        match self {
+            n @ Canonical::Null(_) => Ok(n),
+            Canonical::Bool(bool) => {
+                // NOTE: update to copy to host when adding buffer handle.
+                // Also update other method to copy validity to host.
+                let BoolArrayParts { bits, validity, .. } = bool.into_parts();
+                Ok(Canonical::Bool(BoolArray::from_bit_buffer(bits, validity)))
+            }
+            Canonical::Primitive(prim) => {
+                let PrimitiveArrayParts {
+                    ptype,
+                    buffer,
+                    validity,
+                    ..
+                } = prim.into_parts();
+                Ok(Canonical::Primitive(PrimitiveArray::from_byte_buffer(
+                    buffer.try_into_host()?.await?,
+                    ptype,
+                    validity,
+                )))
+            }
+            Canonical::Decimal(decimal) => {
+                let DecimalArrayParts {
+                    decimal_dtype,
+                    nullability,
+                    values,
+                    values_type,
+                    validity,
+                } = decimal.into_parts();
+                Ok(Canonical::Decimal(unsafe {
+                    DecimalArray::new_unchecked_handle(
+                        BufferHandle::new_host(values.try_into_host()?.await?),
+                        values_type,
+                        decimal_dtype,
+                        validity,
+                    )
+                }))
+            }
+            _ => todo!(),
+        }
+    }
+}
diff --git a/vortex-cuda/src/lib.rs b/vortex-cuda/src/lib.rs
index d77be685b20..c331dc80103 100644
--- a/vortex-cuda/src/lib.rs
+++ b/vortex-cuda/src/lib.rs
@@ -3,12 +3,14 @@
 
 //! CUDA support for Vortex arrays.
 
+mod canonical;
 mod device_buffer;
 pub mod executor;
 mod kernel;
 mod session;
 mod stream;
 
+pub use canonical::CanonicalCudaExt;
 pub use device_buffer::CudaBufferExt;
 pub use device_buffer::CudaDeviceBuffer;
 pub use executor::CudaExecutionCtx;

From 4abf4bd9dd14814c8b32989382dc628f49dfae06 Mon Sep 17 00:00:00 2001
From: Joe Isaacs <joe.isaacs@live.co.uk>
Date: Fri, 23 Jan 2026 19:37:20 +0000
Subject: [PATCH 2/2] feat[cuda]: to_host canonical

Signed-off-by: Joe Isaacs <joe.isaacs@live.co.uk>
---
 vortex-cuda/src/canonical.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/vortex-cuda/src/canonical.rs b/vortex-cuda/src/canonical.rs
index 4dc417f1165..7306c80aec1 100644
--- a/vortex-cuda/src/canonical.rs
+++ b/vortex-cuda/src/canonical.rs
@@ -15,9 +15,12 @@ use vortex_error::VortexResult;
 /// Move all canonical data from to_host from device.
 #[async_trait]
 pub trait CanonicalCudaExt {
-    async fn to_host(self) -> VortexResult<Self>;
+    async fn to_host(self) -> VortexResult<Self>
+    where
+        Self: Sized;
 }
 
+#[async_trait]
 impl CanonicalCudaExt for Canonical {
     async fn to_host(self) -> VortexResult<Self> {
         match self {
@@ -44,10 +47,10 @@ impl CanonicalCudaExt for Canonical {
             Canonical::Decimal(decimal) => {
                 let DecimalArrayParts {
                     decimal_dtype,
-                    nullability,
                     values,
                     values_type,
                     validity,
+                    ..
                 } = decimal.into_parts();
                 Ok(Canonical::Decimal(unsafe {
                     DecimalArray::new_unchecked_handle(