diff --git a/encodings/alp/src/alp/ops.rs b/encodings/alp/src/alp/ops.rs
index a8850744056..58b5ee99360 100644
--- a/encodings/alp/src/alp/ops.rs
+++ b/encodings/alp/src/alp/ops.rs
@@ -15,6 +15,8 @@ use crate::ALPFloat;
 use crate::match_each_alp_float_ptype;
 
 impl OperationsVTable<ALP> for ALP {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ALP>,
         index: usize,
diff --git a/encodings/alp/src/alp_rd/ops.rs b/encodings/alp/src/alp_rd/ops.rs
index edb2fb21186..1433966a01e 100644
--- a/encodings/alp/src/alp_rd/ops.rs
+++ b/encodings/alp/src/alp_rd/ops.rs
@@ -14,6 +14,8 @@ use crate::ALPRDArrayExt;
 use crate::ALPRDArraySlotsExt;
 
 impl OperationsVTable<ALPRD> for ALPRD {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ALPRD>,
         index: usize,
diff --git a/encodings/bytebool/src/array.rs b/encodings/bytebool/src/array.rs
index faa1fea81fa..02bb4fcb2b8 100644
--- a/encodings/bytebool/src/array.rs
+++ b/encodings/bytebool/src/array.rs
@@ -312,6 +312,8 @@ impl ValidityVTable<ByteBool> for ByteBool {
 }
 
 impl OperationsVTable<ByteBool> for ByteBool {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ByteBool>,
         index: usize,
diff --git a/encodings/datetime-parts/src/ops.rs b/encodings/datetime-parts/src/ops.rs
index d99e55c7542..0ee4f9e315c 100644
--- a/encodings/datetime-parts/src/ops.rs
+++ b/encodings/datetime-parts/src/ops.rs
@@ -17,6 +17,8 @@ use crate::timestamp;
 use crate::timestamp::TimestampParts;
 
 impl OperationsVTable<DateTimeParts> for DateTimeParts {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, DateTimeParts>,
         index: usize,
diff --git a/encodings/decimal-byte-parts/src/decimal_byte_parts/mod.rs b/encodings/decimal-byte-parts/src/decimal_byte_parts/mod.rs
index d5b0024f5b7..e1d081ddaca 100644
--- a/encodings/decimal-byte-parts/src/decimal_byte_parts/mod.rs
+++ b/encodings/decimal-byte-parts/src/decimal_byte_parts/mod.rs
@@ -289,6 +289,8 @@ fn to_canonical_decimal(
 }
 
 impl OperationsVTable<DecimalByteParts> for DecimalByteParts {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, DecimalByteParts>,
         index: usize,
diff --git a/encodings/fastlanes/src/bitpacking/vtable/operations.rs b/encodings/fastlanes/src/bitpacking/vtable/operations.rs
index e14b27323c1..2816407ac03 100644
--- a/encodings/fastlanes/src/bitpacking/vtable/operations.rs
+++ b/encodings/fastlanes/src/bitpacking/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::BitPacked;
 use crate::bitpack_decompress;
 use crate::bitpacking::array::BitPackedArrayExt;
 impl OperationsVTable<BitPacked> for BitPacked {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, BitPacked>,
         index: usize,
diff --git a/encodings/fastlanes/src/delta/vtable/operations.rs b/encodings/fastlanes/src/delta/vtable/operations.rs
index 7ed57a0886d..b37760621ea 100644
--- a/encodings/fastlanes/src/delta/vtable/operations.rs
+++ b/encodings/fastlanes/src/delta/vtable/operations.rs
@@ -11,6 +11,8 @@ use vortex_error::VortexResult;
 
 use super::Delta;
 impl OperationsVTable<Delta> for Delta {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Delta>,
         index: usize,
diff --git a/encodings/fastlanes/src/for/vtable/operations.rs b/encodings/fastlanes/src/for/vtable/operations.rs
index 36dac998cbe..361020824d5 100644
--- a/encodings/fastlanes/src/for/vtable/operations.rs
+++ b/encodings/fastlanes/src/for/vtable/operations.rs
@@ -13,6 +13,8 @@ use super::FoR;
 use crate::r#for::array::FoRArrayExt;
 use crate::r#for::array::FoRArraySlotsExt;
 impl OperationsVTable<FoR> for FoR {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, FoR>,
         index: usize,
diff --git a/encodings/fastlanes/src/rle/vtable/operations.rs b/encodings/fastlanes/src/rle/vtable/operations.rs
index ca4d2d39545..ba6a624f1f5 100644
--- a/encodings/fastlanes/src/rle/vtable/operations.rs
+++ b/encodings/fastlanes/src/rle/vtable/operations.rs
@@ -14,6 +14,8 @@ use crate::rle::RLEArrayExt;
 use crate::rle::RLEArraySlotsExt;
 
 impl OperationsVTable<RLE> for RLE {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, RLE>,
         index: usize,
diff --git a/encodings/fastlanes/src/transposed_bool.rs b/encodings/fastlanes/src/transposed_bool.rs
index efb3443cdfc..92da3b3b79c 100644
--- a/encodings/fastlanes/src/transposed_bool.rs
+++ b/encodings/fastlanes/src/transposed_bool.rs
@@ -256,6 +256,8 @@ impl VTable for TransposedBool {
 }
 
 impl OperationsVTable<TransposedBool> for TransposedBool {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, TransposedBool>,
         index: usize,
diff --git a/encodings/fsst/src/ops.rs b/encodings/fsst/src/ops.rs
index b630508ed9e..03560b2c8b8 100644
--- a/encodings/fsst/src/ops.rs
+++ b/encodings/fsst/src/ops.rs
@@ -14,6 +14,8 @@ use crate::FSST;
 use crate::FSSTArrayExt;
 
 impl OperationsVTable<FSST> for FSST {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, FSST>,
         index: usize,
diff --git a/encodings/onpair/src/ops.rs b/encodings/onpair/src/ops.rs
index 728e5a0e6f2..082bc55e199 100644
--- a/encodings/onpair/src/ops.rs
+++ b/encodings/onpair/src/ops.rs
@@ -18,6 +18,8 @@ use crate::decode::code_boundary_at;
 use crate::decode::collect_widened;
 
 impl OperationsVTable<OnPair> for OnPair {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, OnPair>,
         index: usize,
diff --git a/encodings/parquet-variant/src/operations.rs b/encodings/parquet-variant/src/operations.rs
index 8517df27f22..eab80bf63e1 100644
--- a/encodings/parquet-variant/src/operations.rs
+++ b/encodings/parquet-variant/src/operations.rs
@@ -31,6 +31,8 @@ use crate::ParquetVariantArraySlotsExt;
 use crate::vtable::ParquetVariant;
 
 impl OperationsVTable<ParquetVariant> for ParquetVariant {
+    type ProbeState = ();
+
     /// Resolves one row according to the Parquet Variant shredding rules.
     ///
     /// For valid data, a row with both `value` and struct `typed_value` is a partially
diff --git a/encodings/pco/src/array.rs b/encodings/pco/src/array.rs
index 44a6a8e4045..97a17fe6a3c 100644
--- a/encodings/pco/src/array.rs
+++ b/encodings/pco/src/array.rs
@@ -778,6 +778,8 @@ impl ValidityVTable<Pco> for Pco {
 }
 
 impl OperationsVTable<Pco> for Pco {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Pco>,
         index: usize,
diff --git a/encodings/runend/src/ops.rs b/encodings/runend/src/ops.rs
index e2c2e3fc99b..46949d84e1b 100644
--- a/encodings/runend/src/ops.rs
+++ b/encodings/runend/src/ops.rs
@@ -18,6 +18,8 @@ use crate::array::RunEndArrayExt;
 use crate::array::RunEndArraySlotsExt;
 
 impl OperationsVTable<RunEnd> for RunEnd {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, RunEnd>,
         index: usize,
diff --git a/encodings/sequence/src/array.rs b/encodings/sequence/src/array.rs
index a36a1f6edab..f3f44e64f6e 100644
--- a/encodings/sequence/src/array.rs
+++ b/encodings/sequence/src/array.rs
@@ -425,6 +425,8 @@ impl VTable for Sequence {
 }
 
 impl OperationsVTable<Sequence> for Sequence {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Sequence>,
         index: usize,
diff --git a/encodings/sparse/src/ops.rs b/encodings/sparse/src/ops.rs
index 568d8d377d1..acabbb103d5 100644
--- a/encodings/sparse/src/ops.rs
+++ b/encodings/sparse/src/ops.rs
@@ -11,6 +11,8 @@ use crate::Sparse;
 use crate::SparseExt as _;
 
 impl OperationsVTable<Sparse> for Sparse {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Sparse>,
         index: usize,
diff --git a/encodings/zigzag/src/array.rs b/encodings/zigzag/src/array.rs
index ef3165132f4..09076fcbbdf 100644
--- a/encodings/zigzag/src/array.rs
+++ b/encodings/zigzag/src/array.rs
@@ -231,6 +231,8 @@ impl Default for ZigZagData {
 }
 
 impl OperationsVTable<ZigZag> for ZigZag {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ZigZag>,
         index: usize,
diff --git a/encodings/zstd/src/array.rs b/encodings/zstd/src/array.rs
index fb3551e539b..dafe8e820a9 100644
--- a/encodings/zstd/src/array.rs
+++ b/encodings/zstd/src/array.rs
@@ -1588,6 +1588,8 @@ impl ValidityVTable<Zstd> for Zstd {
 }
 
 impl OperationsVTable<Zstd> for Zstd {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Zstd>,
         index: usize,
diff --git a/encodings/zstd/src/zstd_buffers.rs b/encodings/zstd/src/zstd_buffers.rs
index f21deee6f64..51d338777ca 100644
--- a/encodings/zstd/src/zstd_buffers.rs
+++ b/encodings/zstd/src/zstd_buffers.rs
@@ -520,6 +520,8 @@ impl VTable for ZstdBuffers {
 }
 
 impl OperationsVTable<ZstdBuffers> for ZstdBuffers {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ZstdBuffers>,
         index: usize,
diff --git a/vortex-array/src/array/mod.rs b/vortex-array/src/array/mod.rs
index 8b9b2812bfa..9b0b7ab8f95 100644
--- a/vortex-array/src/array/mod.rs
+++ b/vortex-array/src/array/mod.rs
@@ -30,6 +30,8 @@ pub use erased::*;
 
 mod plugin;
 pub use plugin::*;
+mod probe;
+pub use probe::*;
 
 mod foreign;
 pub(crate) use foreign::*;
@@ -497,7 +499,11 @@ impl<V: VTable> DynArrayData for ArrayData<V> {
         ctx: &mut ExecutionCtx,
     ) -> VortexResult<Scalar> {
         let view = unsafe { ArrayView::new_unchecked(this, &self.data) };
-        <V::OperationsVTable as OperationsVTable<V>>::scalar_at(view, index, ctx)
+        <V::OperationsVTable as OperationsVTable<V>>::probe_scalar(
+            &mut ProbeState::once(view),
+            index,
+            ctx,
+        )
     }
 }
 
diff --git a/vortex-array/src/array/probe/array.rs b/vortex-array/src/array/probe/array.rs
new file mode 100644
index 00000000000..acb45fdaf3b
--- /dev/null
+++ b/vortex-array/src/array/probe/array.rs
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+use crate::array::ArrayView;
+use crate::array::VTable;
+
+/// Everything an encoding's `probe_scalar` runs with.
+///
+/// Passed to [`OperationsVTable::probe_scalar`](crate::vtable::OperationsVTable::probe_scalar).
+/// Holds the typed view of the array being read; it owns nothing, so building one per read is
+/// free.
+pub struct ProbeState<'a, V: VTable> {
+    array: ArrayView<'a, V>,
+}
+
+impl<'a, V: VTable> ProbeState<'a, V> {
+    /// State for a single read of `array`.
+    #[inline]
+    pub fn once(array: ArrayView<'a, V>) -> Self {
+        Self { array }
+    }
+
+    /// The typed view of the array being read.
+    #[inline]
+    pub fn array(&self) -> ArrayView<'a, V> {
+        self.array
+    }
+}
diff --git a/vortex-array/src/array/probe/mod.rs b/vortex-array/src/array/probe/mod.rs
new file mode 100644
index 00000000000..c13332f115f
--- /dev/null
+++ b/vortex-array/src/array/probe/mod.rs
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+//! State passed to an encoding's
+//! [`probe_scalar`](crate::vtable::OperationsVTable::probe_scalar).
+
+mod array;
+pub use array::*;
diff --git a/vortex-array/src/array/vtable/operations.rs b/vortex-array/src/array/vtable/operations.rs
index 7f49e683640..96540169e14 100644
--- a/vortex-array/src/array/vtable/operations.rs
+++ b/vortex-array/src/array/vtable/operations.rs
@@ -7,6 +7,7 @@ use vortex_error::vortex_bail;
 use crate::ExecutionCtx;
 use crate::array::ArrayView;
 use crate::array::VTable;
+use crate::array::probe::ProbeState;
 use crate::scalar::Scalar;
 use crate::vtable::NotSupported;
 
@@ -17,6 +18,29 @@ use crate::vtable::NotSupported;
 /// [`ArrayRef`](crate::ArrayRef)
 /// methods perform common checks before dispatching here.
 pub trait OperationsVTable<V: VTable> {
+    /// Encoding-specific state retained across repeated scalar reads.
+    ///
+    /// Built once per retained probe and never for a one-off read. Use `()` when no state is
+    /// needed.
+    type ProbeState: Default + 'static;
+
+    /// Read the non-null scalar at `index` of the array in `state`.
+    ///
+    /// Bounds and validity have been checked; the row is non-null. `state` carries the typed
+    /// view of the array being read. The scalar must retain the source's logical dtype,
+    /// including nullability.
+    ///
+    /// The default preserves the existing scalar path.
+    fn probe_scalar(
+        state: &mut ProbeState<'_, V>,
+        index: usize,
+        ctx: &mut ExecutionCtx,
+    ) -> VortexResult<Scalar> {
+        // FIXME: Remove this default once all encodings have migrated to probe_scalar.
+        Self::scalar_at(state.array(), index, ctx)
+    }
+
+    // FIXME: Deprecate scalar_at once encodings have migrated to probe_scalar.
     /// Fetch the scalar at the given index.
     ///
     /// ## Preconditions
@@ -35,6 +59,8 @@ pub trait OperationsVTable<V: VTable> {
 }
 
 impl<V: VTable> OperationsVTable<V> for NotSupported {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, V>,
         _index: usize,
diff --git a/vortex-array/src/arrays/bool/vtable/operations.rs b/vortex-array/src/arrays/bool/vtable/operations.rs
index c29ab20331b..e1ec02ecbc8 100644
--- a/vortex-array/src/arrays/bool/vtable/operations.rs
+++ b/vortex-array/src/arrays/bool/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::arrays::bool::BoolArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Bool> for Bool {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Bool>,
         index: usize,
diff --git a/vortex-array/src/arrays/chunked/vtable/operations.rs b/vortex-array/src/arrays/chunked/vtable/operations.rs
index 8f9e0867a88..395e8aff70a 100644
--- a/vortex-array/src/arrays/chunked/vtable/operations.rs
+++ b/vortex-array/src/arrays/chunked/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::arrays::chunked::ChunkedArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Chunked> for Chunked {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Chunked>,
         index: usize,
diff --git a/vortex-array/src/arrays/constant/vtable/operations.rs b/vortex-array/src/arrays/constant/vtable/operations.rs
index e3568a9c39f..9c49094f324 100644
--- a/vortex-array/src/arrays/constant/vtable/operations.rs
+++ b/vortex-array/src/arrays/constant/vtable/operations.rs
@@ -10,6 +10,8 @@ use crate::arrays::Constant;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Constant> for Constant {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Constant>,
         _index: usize,
diff --git a/vortex-array/src/arrays/decimal/vtable/operations.rs b/vortex-array/src/arrays/decimal/vtable/operations.rs
index 257f26127ae..aecf6638bd2 100644
--- a/vortex-array/src/arrays/decimal/vtable/operations.rs
+++ b/vortex-array/src/arrays/decimal/vtable/operations.rs
@@ -12,6 +12,8 @@ use crate::scalar::DecimalValue;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Decimal> for Decimal {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Decimal>,
         index: usize,
diff --git a/vortex-array/src/arrays/dict/vtable/operations.rs b/vortex-array/src/arrays/dict/vtable/operations.rs
index 1982a1e0870..d497db0f2f8 100644
--- a/vortex-array/src/arrays/dict/vtable/operations.rs
+++ b/vortex-array/src/arrays/dict/vtable/operations.rs
@@ -12,6 +12,8 @@ use crate::arrays::dict::DictArraySlotsExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Dict> for Dict {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Dict>,
         index: usize,
diff --git a/vortex-array/src/arrays/extension/vtable/operations.rs b/vortex-array/src/arrays/extension/vtable/operations.rs
index 66de94b596a..519ef6088f7 100644
--- a/vortex-array/src/arrays/extension/vtable/operations.rs
+++ b/vortex-array/src/arrays/extension/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::arrays::extension::ExtensionArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Extension> for Extension {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Extension>,
         index: usize,
diff --git a/vortex-array/src/arrays/filter/vtable.rs b/vortex-array/src/arrays/filter/vtable.rs
index 260abe0046c..f5a61ba79d7 100644
--- a/vortex-array/src/arrays/filter/vtable.rs
+++ b/vortex-array/src/arrays/filter/vtable.rs
@@ -200,6 +200,8 @@ impl VTable for Filter {
     }
 }
 impl OperationsVTable<Filter> for Filter {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Filter>,
         index: usize,
diff --git a/vortex-array/src/arrays/fixed_size_list/vtable/operations.rs b/vortex-array/src/arrays/fixed_size_list/vtable/operations.rs
index 9f4cf02fbf8..eca0e45ad95 100644
--- a/vortex-array/src/arrays/fixed_size_list/vtable/operations.rs
+++ b/vortex-array/src/arrays/fixed_size_list/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::arrays::fixed_size_list::FixedSizeListArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<FixedSizeList> for FixedSizeList {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, FixedSizeList>,
         index: usize,
diff --git a/vortex-array/src/arrays/interleave/mod.rs b/vortex-array/src/arrays/interleave/mod.rs
index d29981249d4..fb649cf6e19 100644
--- a/vortex-array/src/arrays/interleave/mod.rs
+++ b/vortex-array/src/arrays/interleave/mod.rs
@@ -389,6 +389,8 @@ impl VTable for Interleave {
 }
 
 impl OperationsVTable<Interleave> for Interleave {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Interleave>,
         index: usize,
diff --git a/vortex-array/src/arrays/list/vtable/operations.rs b/vortex-array/src/arrays/list/vtable/operations.rs
index 02c686cd1f1..668cc18a32f 100644
--- a/vortex-array/src/arrays/list/vtable/operations.rs
+++ b/vortex-array/src/arrays/list/vtable/operations.rs
@@ -13,6 +13,8 @@ use crate::arrays::list::ListArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<List> for List {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, List>,
         index: usize,
diff --git a/vortex-array/src/arrays/listview/vtable/operations.rs b/vortex-array/src/arrays/listview/vtable/operations.rs
index f0cb9539cc3..8608985463d 100644
--- a/vortex-array/src/arrays/listview/vtable/operations.rs
+++ b/vortex-array/src/arrays/listview/vtable/operations.rs
@@ -13,6 +13,8 @@ use crate::arrays::listview::ListViewArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<ListView> for ListView {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ListView>,
         index: usize,
diff --git a/vortex-array/src/arrays/map/vtable/operations.rs b/vortex-array/src/arrays/map/vtable/operations.rs
index d6e8fe87f12..66b8e47a75a 100644
--- a/vortex-array/src/arrays/map/vtable/operations.rs
+++ b/vortex-array/src/arrays/map/vtable/operations.rs
@@ -13,6 +13,8 @@ use crate::arrays::struct_::StructArrayExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Map> for Map {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Map>,
         index: usize,
diff --git a/vortex-array/src/arrays/masked/vtable/operations.rs b/vortex-array/src/arrays/masked/vtable/operations.rs
index c82d0bf03ed..a418e23f217 100644
--- a/vortex-array/src/arrays/masked/vtable/operations.rs
+++ b/vortex-array/src/arrays/masked/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::arrays::masked::MaskedArraySlotsExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Masked> for Masked {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Masked>,
         index: usize,
diff --git a/vortex-array/src/arrays/null/mod.rs b/vortex-array/src/arrays/null/mod.rs
index 8479b7137cc..b4d4536c9cf 100644
--- a/vortex-array/src/arrays/null/mod.rs
+++ b/vortex-array/src/arrays/null/mod.rs
@@ -175,6 +175,8 @@ impl Array<Null> {
 }
 
 impl OperationsVTable<Null> for Null {
+    type ProbeState = ();
+
     fn scalar_at(
         _array: ArrayView<'_, Null>,
         _index: usize,
diff --git a/vortex-array/src/arrays/patched/vtable/operations.rs b/vortex-array/src/arrays/patched/vtable/operations.rs
index 51dd1fc9e3c..bd7440965ab 100644
--- a/vortex-array/src/arrays/patched/vtable/operations.rs
+++ b/vortex-array/src/arrays/patched/vtable/operations.rs
@@ -14,6 +14,8 @@ use crate::optimizer::ArrayOptimizer;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Patched> for Patched {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Patched>,
         index: usize,
diff --git a/vortex-array/src/arrays/piecewise_sequence/vtable.rs b/vortex-array/src/arrays/piecewise_sequence/vtable.rs
index d68a00815f3..d39bd6eccac 100644
--- a/vortex-array/src/arrays/piecewise_sequence/vtable.rs
+++ b/vortex-array/src/arrays/piecewise_sequence/vtable.rs
@@ -145,6 +145,8 @@ impl VTable for PiecewiseSequence {
 }
 
 impl OperationsVTable<PiecewiseSequence> for PiecewiseSequence {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, PiecewiseSequence>,
         index: usize,
diff --git a/vortex-array/src/arrays/primitive/vtable/operations.rs b/vortex-array/src/arrays/primitive/vtable/operations.rs
index ddeaa386485..9501513fb1c 100644
--- a/vortex-array/src/arrays/primitive/vtable/operations.rs
+++ b/vortex-array/src/arrays/primitive/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::match_each_native_ptype;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Primitive> for Primitive {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Primitive>,
         index: usize,
diff --git a/vortex-array/src/arrays/scalar_fn/vtable/operations.rs b/vortex-array/src/arrays/scalar_fn/vtable/operations.rs
index 40d75906356..21af5728572 100644
--- a/vortex-array/src/arrays/scalar_fn/vtable/operations.rs
+++ b/vortex-array/src/arrays/scalar_fn/vtable/operations.rs
@@ -15,6 +15,8 @@ use crate::scalar::Scalar;
 use crate::scalar_fn::VecExecutionArgs;
 
 impl OperationsVTable<ScalarFn> for ScalarFn {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, ScalarFn>,
         index: usize,
diff --git a/vortex-array/src/arrays/shared/vtable.rs b/vortex-array/src/arrays/shared/vtable.rs
index 758d091b557..b1a9a4d7b15 100644
--- a/vortex-array/src/arrays/shared/vtable.rs
+++ b/vortex-array/src/arrays/shared/vtable.rs
@@ -125,6 +125,8 @@ impl VTable for Shared {
     }
 }
 impl OperationsVTable<Shared> for Shared {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Shared>,
         index: usize,
diff --git a/vortex-array/src/arrays/slice/vtable.rs b/vortex-array/src/arrays/slice/vtable.rs
index c88c28a9a4d..c09d81ee4f1 100644
--- a/vortex-array/src/arrays/slice/vtable.rs
+++ b/vortex-array/src/arrays/slice/vtable.rs
@@ -169,6 +169,8 @@ impl VTable for Slice {
     }
 }
 impl OperationsVTable<Slice> for Slice {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Slice>,
         index: usize,
diff --git a/vortex-array/src/arrays/struct_/vtable/operations.rs b/vortex-array/src/arrays/struct_/vtable/operations.rs
index b491e231520..54d086bf7c9 100644
--- a/vortex-array/src/arrays/struct_/vtable/operations.rs
+++ b/vortex-array/src/arrays/struct_/vtable/operations.rs
@@ -12,6 +12,8 @@ use crate::scalar::Scalar;
 use crate::scalar::ScalarValue;
 
 impl OperationsVTable<Struct> for Struct {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Struct>,
         index: usize,
diff --git a/vortex-array/src/arrays/union/vtable/operations.rs b/vortex-array/src/arrays/union/vtable/operations.rs
index 39ba95ed4ee..78b9759ab1c 100644
--- a/vortex-array/src/arrays/union/vtable/operations.rs
+++ b/vortex-array/src/arrays/union/vtable/operations.rs
@@ -14,6 +14,8 @@ use crate::arrays::union::UnionArraySlotsExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Union> for Union {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Union>,
         index: usize,
diff --git a/vortex-array/src/arrays/varbin/vtable/operations.rs b/vortex-array/src/arrays/varbin/vtable/operations.rs
index e11043e605a..cc5090d8912 100644
--- a/vortex-array/src/arrays/varbin/vtable/operations.rs
+++ b/vortex-array/src/arrays/varbin/vtable/operations.rs
@@ -12,6 +12,8 @@ use crate::arrays::varbin::varbin_scalar;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<VarBin> for VarBin {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, VarBin>,
         index: usize,
diff --git a/vortex-array/src/arrays/varbinview/vtable/operations.rs b/vortex-array/src/arrays/varbinview/vtable/operations.rs
index 1a1f20a0dbe..53866d29fb5 100644
--- a/vortex-array/src/arrays/varbinview/vtable/operations.rs
+++ b/vortex-array/src/arrays/varbinview/vtable/operations.rs
@@ -11,6 +11,8 @@ use crate::arrays::varbin::varbin_scalar;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<VarBinView> for VarBinView {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, VarBinView>,
         index: usize,
diff --git a/vortex-array/src/arrays/variant/vtable/operations.rs b/vortex-array/src/arrays/variant/vtable/operations.rs
index c7f7d36fd97..ed61223d637 100644
--- a/vortex-array/src/arrays/variant/vtable/operations.rs
+++ b/vortex-array/src/arrays/variant/vtable/operations.rs
@@ -12,6 +12,8 @@ use crate::arrays::variant::VariantArraySlotsExt;
 use crate::scalar::Scalar;
 
 impl OperationsVTable<Variant> for Variant {
+    type ProbeState = ();
+
     fn scalar_at(
         array: ArrayView<'_, Variant>,
         index: usize,
diff --git a/vortex-python/src/arrays/py/vtable.rs b/vortex-python/src/arrays/py/vtable.rs
index 5ec749d3a5f..5697d5a7574 100644
--- a/vortex-python/src/arrays/py/vtable.rs
+++ b/vortex-python/src/arrays/py/vtable.rs
@@ -122,6 +122,8 @@ impl VTable for PythonVTable {
 }
 
 impl OperationsVTable<PythonVTable> for PythonVTable {
+    type ProbeState = ();
+
     fn scalar_at(
         _array: ArrayView<'_, PythonVTable>,
         _index: usize,