should be it

external/duckdb/benchmark/tpch/union/q01_union.benchmark

@@ -0,0 +1,42 @@
+# name: benchmark/tpch/union/q01_union.benchmark
+# description: Union of separate tables into a single aggregate
+# group: [union]
+
+include benchmark/tpch/tpch_load.benchmark.in
+
+name Lineitem Union Q01
+group union
+subgroup tpch
+
+run
+SELECT
+    l_returnflag,
+    l_linestatus,
+    sum(l_quantity) AS sum_qty,
+    sum(l_extendedprice) AS sum_base_price,
+    sum(l_extendedprice * (1 - l_discount)) AS sum_disc_price,
+    sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) AS sum_charge,
+    avg(l_quantity) AS avg_qty,
+    avg(l_extendedprice) AS avg_price,
+    avg(l_discount) AS avg_disc,
+    count(*) AS count_order
+FROM
+    (
+		SELECT * FROM lineitem WHERE l_shipdate <= DATE '1990-09-02'
+		UNION ALL
+		SELECT * FROM lineitem WHERE l_shipdate > DATE '1990-09-02' AND l_shipdate <= DATE '1992-09-02'
+		UNION ALL
+		SELECT * FROM lineitem WHERE l_shipdate > DATE '1992-09-02' AND l_shipdate <= DATE '1994-09-02'
+		UNION ALL
+		SELECT * FROM lineitem WHERE l_shipdate > DATE '1994-09-02' AND l_shipdate <= DATE '1996-09-02'
+		UNION ALL
+		SELECT * FROM lineitem WHERE l_shipdate > DATE '1996-09-02' AND l_shipdate <= DATE '1998-09-02'
+	) lineitem
+GROUP BY
+    l_returnflag,
+    l_linestatus
+ORDER BY
+    l_returnflag,
+    l_linestatus;
+
+result extension/tpch/dbgen/answers/sf1/q01.csv sf=1

external/duckdb/benchmark/tpch/union/ungrouped_aggregate_union.benchmark

@@ -0,0 +1,33 @@
+# name: benchmark/tpch/union/ungrouped_aggregate_union.benchmark
+# description: Ungrouped aggregates split over separate unions
+# group: [union]
+
+include benchmark/tpch/tpch_load.benchmark.in
+
+name Lineitem Union Ungrouped Aggregate
+group union
+subgroup tpch
+
+run
+SELECT sum(l_quantity) AS sum FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+UNION ALL
+SELECT sum(l_extendedprice) FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+UNION ALL
+SELECT sum(l_extendedprice * (1 - l_discount)) FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+UNION ALL
+SELECT sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+UNION ALL
+SELECT avg(l_quantity) FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+UNION ALL
+SELECT avg(l_extendedprice) FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+UNION ALL
+SELECT count(*) FROM lineitem WHERE l_shipdate <= CAST('1998-09-02' AS date)
+
+result I sf=1
+150921317.0
+226343830189.75
+215030862295.13
+223635377438.35
+25.50815444231315
+38255.78448632836
+5916591.0