apache · brancz · Mar 6, 2026
diff --git a/datafusion/common/src/scalar/mod.rs b/datafusion/common/src/scalar/mod.rs
@@ -3675,6 +3675,22 @@ impl ScalarValue {
                     .with_field(field)
                     .build_fixed_size_list_scalar(list_size)
             }
+            DataType::ListView(field) => {
+                let list_array = array.as_list_view::<i32>();
+                let nested_array = list_array.value(index);
+                // Store as List scalar since ScalarValue has no ListView variant.
+                SingleRowListArrayBuilder::new(nested_array)
+                    .with_field(field)
+                    .build_list_scalar()
+            }
+            DataType::LargeListView(field) => {
+                let list_array = array.as_list_view::<i64>();
+                let nested_array = list_array.value(index);
+                // Store as LargeList scalar since ScalarValue has no LargeListView variant.
+                SingleRowListArrayBuilder::new(nested_array)
+                    .with_field(field)
+                    .build_large_list_scalar()
+            }
             DataType::Date32 => typed_cast!(array, index, as_date32_array, Date32)?,
             DataType::Date64 => typed_cast!(array, index, as_date64_array, Date64)?,
             DataType::Time32(TimeUnit::Second) => {

diff --git a/datafusion/expr/src/expr_schema.rs b/datafusion/expr/src/expr_schema.rs
@@ -141,7 +141,9 @@ impl ExprSchemable for Expr {
                 match arg_data_type {
                     DataType::List(field)
                     | DataType::LargeList(field)
-                    | DataType::FixedSizeList(field, _) => Ok(field.data_type().clone()),
+                    | DataType::FixedSizeList(field, _)
+                    | DataType::ListView(field)
+                    | DataType::LargeListView(field) => Ok(field.data_type().clone()),
                     DataType::Struct(_) => Ok(arg_data_type),
                     DataType::Null => {
                         not_impl_err!("unnest() does not support null yet")

diff --git a/datafusion/expr/src/logical_plan/plan.rs b/datafusion/expr/src/logical_plan/plan.rs
@@ -4194,7 +4194,9 @@ impl Unnest {
                                 }
                                 DataType::List(_)
                                 | DataType::FixedSizeList(_, _)
-                                | DataType::LargeList(_) => {
+                                | DataType::LargeList(_)
+                                | DataType::ListView(_)
+                                | DataType::LargeListView(_) => {
                                     list_columns.push((
                                         index,
                                         ColumnUnnestList {
@@ -4269,7 +4271,11 @@ fn get_unnested_columns(
     let mut qualified_columns = Vec::with_capacity(1);
 
     match data_type {
-        DataType::List(_) | DataType::FixedSizeList(_, _) | DataType::LargeList(_) => {
+        DataType::List(_)
+        | DataType::FixedSizeList(_, _)
+        | DataType::LargeList(_)
+        | DataType::ListView(_)
+        | DataType::LargeListView(_) => {
             let data_type = get_unnested_list_datatype_recursive(data_type, depth)?;
             let new_field = Arc::new(Field::new(
                 col_name, data_type,
@@ -4306,7 +4312,9 @@ fn get_unnested_list_datatype_recursive(
     match data_type {
         DataType::List(field)
         | DataType::FixedSizeList(field, _)
-        | DataType::LargeList(field) => {
+        | DataType::LargeList(field)
+        | DataType::ListView(field)
+        | DataType::LargeListView(field) => {
             if depth == 1 {
                 return Ok(field.data_type().clone());
             }

diff --git a/datafusion/physical-plan/src/unnest.rs b/datafusion/physical-plan/src/unnest.rs
@@ -33,7 +33,8 @@ use crate::{
 
 use arrow::array::{
     Array, ArrayRef, AsArray, BooleanBufferBuilder, FixedSizeListArray, Int64Array,
-    LargeListArray, ListArray, PrimitiveArray, Scalar, StructArray, new_null_array,
+    LargeListArray, LargeListViewArray, ListArray, ListViewArray, PrimitiveArray, Scalar,
+    StructArray, new_null_array,
 };
 use arrow::compute::kernels::length::length;
 use arrow::compute::kernels::zip::zip;
@@ -845,6 +846,30 @@ impl ListArrayType for FixedSizeListArray {
     }
 }
 
+impl ListArrayType for ListViewArray {
+    fn values(&self) -> &ArrayRef {
+        self.values()
+    }
+
+    fn value_offsets(&self, row: usize) -> (i64, i64) {
+        let offset = self.value_offsets()[row] as i64;
+        let size = self.value_sizes()[row] as i64;
+        (offset, offset + size)
+    }
+}
+
+impl ListArrayType for LargeListViewArray {
+    fn values(&self) -> &ArrayRef {
+        self.values()
+    }
+
+    fn value_offsets(&self, row: usize) -> (i64, i64) {
+        let offset = self.value_offsets()[row];
+        let size = self.value_sizes()[row];
+        (offset, offset + size)
+    }
+}
+
 /// Unnest multiple list arrays according to the length array.
 fn unnest_list_arrays(
     list_arrays: &[ArrayRef],
@@ -861,6 +886,12 @@ fn unnest_list_arrays(
             DataType::FixedSizeList(_, _) => {
                 Ok(list_array.as_fixed_size_list() as &dyn ListArrayType)
             }
+            DataType::ListView(_) => {
+                Ok(list_array.as_list_view::<i32>() as &dyn ListArrayType)
+            }
+            DataType::LargeListView(_) => {
+                Ok(list_array.as_list_view::<i64>() as &dyn ListArrayType)
+            }
             other => exec_err!("Invalid unnest datatype {other }"),
         })
         .collect::<Result<Vec<_>>>()?;

diff --git a/datafusion/sql/src/expr/function.rs b/datafusion/sql/src/expr/function.rs
@@ -905,6 +905,8 @@ impl<S: ContextProvider> SqlToRel<'_, S> {
             DataType::List(_)
             | DataType::LargeList(_)
             | DataType::FixedSizeList(_, _)
+            | DataType::ListView(_)
+            | DataType::LargeListView(_)
             | DataType::Struct(_) => Ok(()),
             DataType::Null => {
                 not_impl_err!("unnest() does not support null yet")

diff --git a/datafusion/sql/src/utils.rs b/datafusion/sql/src/utils.rs
@@ -466,7 +466,9 @@ impl RecursiveUnnestRewriter<'_> {
             }
             DataType::List(_)
             | DataType::FixedSizeList(_, _)
-            | DataType::LargeList(_) => {
+            | DataType::LargeList(_)
+            | DataType::ListView(_)
+            | DataType::LargeListView(_) => {
                 push_projection_dedupl(
                     self.inner_projection_exprs,
                     expr_in_unnest.clone().alias(placeholder_name.clone()),

diff --git a/datafusion/sqllogictest/test_files/unnest.slt b/datafusion/sqllogictest/test_files/unnest.slt
@@ -1233,3 +1233,99 @@ physical_plan
 # cleanup
 statement ok
 drop table t;
+
+########################################
+# Unnest ListView / LargeListView Tests #
+########################################
+
+## Basic unnest ListView in select list
+query I
+select unnest(arrow_cast([1,2,3], 'ListView(Int64)'));
+----
+1
+2
+3
+
+## Basic unnest ListView in from clause
+query I
+select * from unnest(arrow_cast([1,2,3], 'ListView(Int64)'));
+----
+1
+2
+3
+
+## Basic unnest LargeListView in select list
+query I
+select unnest(arrow_cast([1,2,3], 'LargeListView(Int64)'));
+----
+1
+2
+3
+
+## Basic unnest LargeListView in from clause
+query I
+select * from unnest(arrow_cast([1,2,3], 'LargeListView(Int64)'));
+----
+1
+2
+3
+
+## Unnest ListView with range
+query I
+select unnest(arrow_cast(range(1, 3), 'ListView(Int64)'));
+----
+1
+2
+
+## Unnest LargeListView with range
+query I
+select * from unnest(arrow_cast(range(1, 3), 'LargeListView(Int64)'));
+----
+1
+2
+
+## Multiple unnest with ListView columns from a table
+query III
+select
+    unnest(column1),
+    unnest(arrow_cast(column2, 'ListView(Int64)')),
+    unnest(arrow_cast(column4, 'LargeListView(Int64)'))
+from unnest_table where column4 is not null;
+----
+1 7 13
+2 NULL 14
+3 NULL NULL
+4 8 15
+5 9 16
+NULL 10 NULL
+NULL NULL 17
+NULL NULL 18
+
+## Unnest ListView with null elements
+query I
+select unnest(arrow_cast([1, null, 3], 'ListView(Int64)'));
+----
+1
+NULL
+3
+
+## Unnest empty ListView
+query I
+select unnest(arrow_cast([], 'ListView(Int64)'));
+----
+
+## Unnest ListView of strings
+query T
+select unnest(arrow_cast(['a','b','c'], 'ListView(Utf8)'));
+----
+a
+b
+c
+
+## Unnest LargeListView of strings
+query T
+select unnest(arrow_cast(['a','b','c'], 'LargeListView(Utf8)'));
+----
+a
+b
+c