should be it

external/duckdb/test/optimizer/topn/complex_top_n.test

@@ -0,0 +1,69 @@
+# name: test/optimizer/topn/complex_top_n.test
+# description: topN
+# group: [topn]
+
+require vector_size 1024
+
+set seed 0.42
+
+statement ok
+create table CUSTOMERVIEW as select range customer_id, range*random()::INT % 3 as customer_priority from range(1000, 4000); 
+
+statement ok
+create table OrderView as select range order_id, ((random()*2::INT)%2)::BOOL order_isExpeditedShipped, range + (random() * 3)::INT order_customerId from range(1000, 4000);
+
+statement ok
+create table OrderItemView as select random()*25 orderItem_quantity, range orderItem_orderId from range(1000, 4000);
+
+statement ok
+create table CREDITCARDVIEW as select range CREDITCARD_CUSTOMERID from range(1000, 4000); 
+
+query III
+WITH CTE AS (
+  SELECT J1P, CUSTOMER_PRIORITY, CUSTOMER_ID FROM CUSTOMERVIEW
+  LEFT JOIN (
+    SELECT ORDER_CUSTOMERID, SUM(ORDERITEMVIEW.ORDERITEM_QUANTITY) AS J1P FROM ORDERVIEW
+    LEFT JOIN ORDERITEMVIEW ON (ORDERVIEW.ORDER_ID = ORDERITEMVIEW.ORDERITEM_ORDERID)
+    WHERE (ORDERVIEW.ORDER_ISEXPEDITEDSHIPPED IS TRUE)
+    GROUP BY ORDERVIEW.ORDER_CUSTOMERID
+  ) AS J1J ON (J1J.ORDER_CUSTOMERID = CUSTOMERVIEW.CUSTOMER_ID)
+  ORDER BY CUSTOMER_PRIORITY ASC, CUSTOMER_ID ASC
+  LIMIT 50 OFFSET 50
+) SELECT J1P, Q2P, Q3P FROM CTE
+LEFT JOIN (
+  SELECT ORDER_CUSTOMERID FROM ORDERVIEW
+) AS Q1J ON (Q1J.ORDER_CUSTOMERID = CTE.CUSTOMER_ID)
+LEFT JOIN (
+  SELECT CREDITCARD_CUSTOMERID AS Q2P FROM CREDITCARDVIEW
+) AS Q2J ON (Q2J.Q2P = CTE.CUSTOMER_ID)
+LEFT JOIN (
+  SELECT ORDER_CUSTOMERID Q3P FROM ORDERVIEW
+  LEFT JOIN ORDERITEMVIEW ON ORDERVIEW.ORDER_ID = ORDERITEM_ORDERID
+) AS Q3J ON (Q3J.Q3P = CTE.CUSTOMER_ID) order by all;
+----
+351 values hashing to 4cba82d74d151aef44c26dc8693f5dca
+
+query II
+explain WITH CTE AS (
+  SELECT J1P, CUSTOMER_PRIORITY, CUSTOMER_ID FROM CUSTOMERVIEW
+  LEFT JOIN (
+    SELECT ORDER_CUSTOMERID, SUM(ORDERITEMVIEW.ORDERITEM_QUANTITY) AS J1P FROM ORDERVIEW
+    LEFT JOIN ORDERITEMVIEW ON (ORDERVIEW.ORDER_ID = ORDERITEMVIEW.ORDERITEM_ORDERID)
+    WHERE (ORDERVIEW.ORDER_ISEXPEDITEDSHIPPED IS TRUE)
+    GROUP BY ORDERVIEW.ORDER_CUSTOMERID
+  ) AS J1J ON (J1J.ORDER_CUSTOMERID = CUSTOMERVIEW.CUSTOMER_ID)
+  ORDER BY CUSTOMER_PRIORITY ASC
+  LIMIT 50 OFFSET 50
+) SELECT J1P, Q2P, Q3P FROM CTE
+LEFT JOIN (
+  SELECT ORDER_CUSTOMERID FROM ORDERVIEW
+) AS Q1J ON (Q1J.ORDER_CUSTOMERID = CTE.CUSTOMER_ID)
+LEFT JOIN (
+  SELECT CREDITCARD_CUSTOMERID AS Q2P FROM CREDITCARDVIEW
+) AS Q2J ON (Q2J.Q2P = CTE.CUSTOMER_ID)
+LEFT JOIN (
+  SELECT ORDER_CUSTOMERID Q3P FROM ORDERVIEW
+  LEFT JOIN ORDERITEMVIEW ON ORDERVIEW.ORDER_ID = ORDERITEM_ORDERID
+) AS Q3J ON (Q3J.Q3P = CTE.CUSTOMER_ID);
+----
+physical_plan	<REGEX>:.*TOP_N.*

external/duckdb/test/optimizer/topn/topn_optimizer.test

@@ -0,0 +1,75 @@
+# name: test/optimizer/topn/topn_optimizer.test
+# description: Test Top N optimization
+# group: [topn]
+
+statement ok
+CREATE TABLE integers(i INTEGER, j INTEGER)
+
+statement ok
+PRAGMA explain_output = OPTIMIZED_ONLY;
+
+# standalone limit
+query II
+EXPLAIN SELECT i FROM integers LIMIT 4
+----
+logical_opt	<REGEX>:.*LIMIT.*
+
+# standalone order by
+query II
+EXPLAIN SELECT i FROM integers ORDER BY i
+----
+logical_opt	<REGEX>:.*ORDER.*
+
+# order by + limit is transformed into top-n
+query II
+EXPLAIN SELECT i FROM integers ORDER BY i LIMIT 4
+----
+logical_opt	<REGEX>:.*TOP_N.*
+
+# also works with offset
+query II
+EXPLAIN SELECT i FROM integers ORDER BY i LIMIT 4 OFFSET 3
+----
+logical_opt	<REGEX>:.*TOP_N.*
+
+# only offset but no limit: no top-n
+query II
+EXPLAIN SELECT i FROM integers ORDER BY i OFFSET 3
+----
+logical_opt	<!REGEX>:.*TOP_N.*
+
+# only limit, but in subquery with projection pull up optimization
+query II
+EXPLAIN SELECT * FROM (SELECT * FROM range(100000000) AS _(x) ORDER BY x) AS cte LIMIT 10
+----
+logical_opt	<REGEX>:.*TOP_N.*
+
+require no_alternative_verify
+
+# top n optimization with more complex projection pull up
+query II
+EXPLAIN
+WITH cte1 AS (SELECT range%2000 a,
+					(range%2000 + 2000) b,
+					(range%2000 + 4000) c,
+					(range%2000 + 6000) d
+			FROM range(10000) ORDER BY range),
+	cte2 as (select *, a as x, b as y, c as z from cte1),
+	cte3 as (select *, a as l, b as m, c as n, d as o from cte2)
+SELECT * FROM cte3 LIMIT 4;
+----
+logical_opt	<REGEX>:.*TOP_N.*
+
+
+statement ok
+create table large_table as select range a from range(100000);
+
+query II
+EXPLAIN select * from large_table order by a limit 100;
+----
+logical_opt	<REGEX>:.*TOP_N.*
+
+query II
+EXPLAIN select * from large_table order by a limit 10000;
+----
+logical_opt	<!REGEX>:.*TOP_N.*