1 files changed, 12 insertions, 0 deletions
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 11c1929bef5..6d532398bd6 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -343,3 +343,15 @@ SELECT EXTRACT(CENTURY FROM INTERVAL '100 y');
 SELECT EXTRACT(CENTURY FROM INTERVAL '99 y');
 SELECT EXTRACT(CENTURY FROM INTERVAL '-99 y');
 SELECT EXTRACT(CENTURY FROM INTERVAL '-100 y');
+
+-- date_part implementation is mostly the same as extract, so only
+-- test a few cases for additional coverage.
+SELECT f1,
+    date_part('microsecond', f1) AS microsecond,
+    date_part('millisecond', f1) AS millisecond,
+    date_part('second', f1) AS second,
+    date_part('epoch', f1) AS epoch
+    FROM INTERVAL_TBL;
+
+-- internal overflow test case
+SELECT extract(epoch from interval '1000000000 days');