Extend datatype semantic equality check to include timestamps (#17777)

* Extend datatype semantic equality to include timestamps

* test

* Respond to comments

* cargo fmt

---------

Co-authored-by: Shiv Bhatia <sbhatia@palantir.com>

Author: shivbhatia10

datafusion/common/src/dfschema.rs

@@ -747,7 +747,8 @@ impl DFSchema {
     }
 
     /// Returns true of two [`DataType`]s are semantically equal (same
-    /// name and type), ignoring both metadata and nullability, and decimal precision/scale.
+    /// name and type), ignoring both metadata and nullability, decimal precision/scale,
+    /// and timezone time units/timezones.
     ///
     /// request to upstream: <https://github.com/apache/arrow-rs/issues/3199>
     pub fn datatype_is_semantically_equal(dt1: &DataType, dt2: &DataType) -> bool {
@@ -814,6 +815,10 @@ impl DFSchema {
                 DataType::Decimal256(_l_precision, _l_scale),
                 DataType::Decimal256(_r_precision, _r_scale),
             ) => true,
+            (
+                DataType::Timestamp(_l_time_unit, _l_timezone),
+                DataType::Timestamp(_r_time_unit, _r_timezone),
+            ) => true,
             _ => dt1 == dt2,
         }
     }
@@ -1811,6 +1816,15 @@ mod tests {
             &DataType::Decimal256(2, 1),
         ));
 
+        // Any two timestamp types should match
+        assert!(DFSchema::datatype_is_semantically_equal(
+            &DataType::Timestamp(
+                arrow::datatypes::TimeUnit::Microsecond,
+                Some("UTC".into())
+            ),
+            &DataType::Timestamp(arrow::datatypes::TimeUnit::Millisecond, None),
+        ));
+
         // Test lists
 
         // Succeeds if both have the same element type, disregards names and nullability