Fix distinct operator for UUID

Cherry-pick of  trinodb/trino#1180 by guyco33
Co-authored-by: Guy Cohen <guyco33@gmail.com>

Author: 2 people

presto-main/src/main/java/com/facebook/presto/type/UuidOperators.java

@@ -199,7 +199,7 @@ public static boolean isDistinctFrom(
             if (left.isNull(leftPosition)) {
                 return false;
             }
-            return left.compareTo(leftPosition, 0, UUID.getFixedSize(), right, rightPosition, 0, UUID.getFixedSize()) != 0;
+            return !UUID.equalTo(left, leftPosition, right, rightPosition);
         }
     }
 

presto-main/src/test/java/com/facebook/presto/sql/query/TestDistinctAggregations.java

@@ -272,4 +272,14 @@ public void testMixedDistinctWithFilter()
                         "FROM (VALUES (1, 3), (2, 4), (2, 4), (4, 5)) t (x, y)",
                 "VALUES (BIGINT '0', CAST(NULL AS BIGINT))");
     }
+
+    @Test
+    public void testUuidDistinct()
+    {
+        assertions.assertQuery(
+                "SELECT DISTINCT uuid_col " +
+                "FROM (VALUES (UUID'be0b0518-35a1-4d10-b7f1-1b61355fa741')," +
+                "             (UUID'be0b0518-35a1-4d10-b7f1-1b61355fa741')) AS t (uuid_col)",
+                "VALUES UUID'be0b0518-35a1-4d10-b7f1-1b61355fa741'");
+    }
 }