diff --git a/datafusion/physical-expr-common/src/expressions/column.rs b/datafusion/physical-expr-common/src/expressions/column.rs
index d972d35b9e4e..5397599ea2dc 100644
--- a/datafusion/physical-expr-common/src/expressions/column.rs
+++ b/datafusion/physical-expr-common/src/expressions/column.rs
@@ -135,3 +135,49 @@ impl Column {
 pub fn col(name: &str, schema: &Schema) -> Result<Arc<dyn PhysicalExpr>> {
     Ok(Arc::new(Column::new_with_schema(name, schema)?))
 }
+
+#[cfg(test)]
+mod test {
+    use super::Column;
+    use crate::physical_expr::PhysicalExpr;
+
+    use arrow::array::StringArray;
+    use arrow::datatypes::{DataType, Field, Schema};
+    use arrow::record_batch::RecordBatch;
+    use datafusion_common::Result;
+
+    use std::sync::Arc;
+
+    #[test]
+    fn out_of_bounds_data_type() {
+        let schema = Schema::new(vec![Field::new("foo", DataType::Utf8, true)]);
+        let col = Column::new("id", 9);
+        let error = col.data_type(&schema).expect_err("error").strip_backtrace();
+        assert!("Internal error: PhysicalExpr Column references column 'id' at index 9 (zero-based) \
+            but input schema only has 1 columns: [\"foo\"].\nThis was likely caused by a bug in \
+            DataFusion's code and we would welcome that you file an bug report in our issue tracker".starts_with(&error))
+    }
+
+    #[test]
+    fn out_of_bounds_nullable() {
+        let schema = Schema::new(vec![Field::new("foo", DataType::Utf8, true)]);
+        let col = Column::new("id", 9);
+        let error = col.nullable(&schema).expect_err("error").strip_backtrace();
+        assert!("Internal error: PhysicalExpr Column references column 'id' at index 9 (zero-based) \
+            but input schema only has 1 columns: [\"foo\"].\nThis was likely caused by a bug in \
+            DataFusion's code and we would welcome that you file an bug report in our issue tracker".starts_with(&error))
+    }
+
+    #[test]
+    fn out_of_bounds_evaluate() -> Result<()> {
+        let schema = Schema::new(vec![Field::new("foo", DataType::Utf8, true)]);
+        let data: StringArray = vec!["data"].into();
+        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(data)])?;
+        let col = Column::new("id", 9);
+        let error = col.evaluate(&batch).expect_err("error").strip_backtrace();
+        assert!("Internal error: PhysicalExpr Column references column 'id' at index 9 (zero-based) \
+            but input schema only has 1 columns: [\"foo\"].\nThis was likely caused by a bug in \
+            DataFusion's code and we would welcome that you file an bug report in our issue tracker".starts_with(&error));
+        Ok(())
+    }
+}
diff --git a/datafusion/physical-expr/src/expressions/mod.rs b/datafusion/physical-expr/src/expressions/mod.rs
index fa80bc9873f0..5a2bcb63b18e 100644
--- a/datafusion/physical-expr/src/expressions/mod.rs
+++ b/datafusion/physical-expr/src/expressions/mod.rs
@@ -20,7 +20,6 @@
 #[macro_use]
 mod binary;
 mod case;
-mod column;
 mod in_list;
 mod is_not_null;
 mod is_null;
@@ -29,6 +28,7 @@ mod negative;
 mod no_op;
 mod not;
 mod try_cast;
+mod unknown_column;
 
 /// Module with some convenient methods used in expression building
 pub mod helpers {
@@ -48,7 +48,6 @@ pub use crate::PhysicalSortExpr;
 
 pub use binary::{binary, BinaryExpr};
 pub use case::{case, CaseExpr};
-pub use column::UnKnownColumn;
 pub use datafusion_expr::utils::format_state_name;
 pub use datafusion_physical_expr_common::expressions::column::{col, Column};
 pub use datafusion_physical_expr_common::expressions::literal::{lit, Literal};
@@ -61,3 +60,4 @@ pub use negative::{negative, NegativeExpr};
 pub use no_op::NoOp;
 pub use not::{not, NotExpr};
 pub use try_cast::{try_cast, TryCastExpr};
+pub use unknown_column::UnKnownColumn;
diff --git a/datafusion/physical-expr/src/expressions/column.rs b/datafusion/physical-expr/src/expressions/unknown_column.rs
similarity index 56%
rename from datafusion/physical-expr/src/expressions/column.rs
rename to datafusion/physical-expr/src/expressions/unknown_column.rs
index ab43201ceb75..cb7221e7fa15 100644
--- a/datafusion/physical-expr/src/expressions/column.rs
+++ b/datafusion/physical-expr/src/expressions/unknown_column.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-//! Column expression
+//! UnKnownColumn expression
 
 use std::any::Any;
 use std::hash::{Hash, Hasher};
@@ -100,49 +100,3 @@ impl PartialEq<dyn Any> for UnKnownColumn {
         false
     }
 }
-
-#[cfg(test)]
-mod test {
-    use crate::expressions::Column;
-    use crate::PhysicalExpr;
-
-    use arrow::array::StringArray;
-    use arrow::datatypes::{DataType, Field, Schema};
-    use arrow::record_batch::RecordBatch;
-    use datafusion_common::Result;
-
-    use std::sync::Arc;
-
-    #[test]
-    fn out_of_bounds_data_type() {
-        let schema = Schema::new(vec![Field::new("foo", DataType::Utf8, true)]);
-        let col = Column::new("id", 9);
-        let error = col.data_type(&schema).expect_err("error").strip_backtrace();
-        assert!("Internal error: PhysicalExpr Column references column 'id' at index 9 (zero-based) \
-            but input schema only has 1 columns: [\"foo\"].\nThis was likely caused by a bug in \
-            DataFusion's code and we would welcome that you file an bug report in our issue tracker".starts_with(&error))
-    }
-
-    #[test]
-    fn out_of_bounds_nullable() {
-        let schema = Schema::new(vec![Field::new("foo", DataType::Utf8, true)]);
-        let col = Column::new("id", 9);
-        let error = col.nullable(&schema).expect_err("error").strip_backtrace();
-        assert!("Internal error: PhysicalExpr Column references column 'id' at index 9 (zero-based) \
-            but input schema only has 1 columns: [\"foo\"].\nThis was likely caused by a bug in \
-            DataFusion's code and we would welcome that you file an bug report in our issue tracker".starts_with(&error))
-    }
-
-    #[test]
-    fn out_of_bounds_evaluate() -> Result<()> {
-        let schema = Schema::new(vec![Field::new("foo", DataType::Utf8, true)]);
-        let data: StringArray = vec!["data"].into();
-        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(data)])?;
-        let col = Column::new("id", 9);
-        let error = col.evaluate(&batch).expect_err("error").strip_backtrace();
-        assert!("Internal error: PhysicalExpr Column references column 'id' at index 9 (zero-based) \
-            but input schema only has 1 columns: [\"foo\"].\nThis was likely caused by a bug in \
-            DataFusion's code and we would welcome that you file an bug report in our issue tracker".starts_with(&error));
-        Ok(())
-    }
-}