Internal duckdb#215: Serial Unordered Scans

* Only use parallel scans for ordered partitions - otherwise the results can be very non-deterministic.
* Make some tests use complete orderings so the expecteds continue to match.
* Disable vector size 2 for moving MODE until we can determine the problem

src/common/sort/partition_state.cpp

@@ -429,7 +429,11 @@ bool PartitionGlobalMergeState::TryPrepareNextStage() {
 
 	switch (stage) {
 	case PartitionSortStage::INIT:
-		total_tasks = num_threads;
+		//	If the partitions are unordered, don't scan in parallel
+		//	because it produces non-deterministic orderings.
+		//	This can theoretically happen with ORDER BY,
+		//	but that is something the query should be explicit about.
+		total_tasks = sink.orders.size() > sink.partitions.size() ? num_threads : 1;
 		stage = PartitionSortStage::SCAN;
 		return true;
 

test/sql/function/list/lambdas/transform.test

@@ -279,7 +279,7 @@ query III
 select list_transform(bb, x->[x,b]), bb, b
 from (select list(b) over wind as bb, first(b) over wind as b
     from test window wind as
-        (order by a asc rows between 4 preceding and current row)
+        (order by a asc, b asc rows between 4 preceding and current row)
     qualify row_number() over wind >4);
 ----
 [[2, 2], [3, 2], [4, 2], [2, 2], [3, 2]]	[2, 3, 4, 2, 3]	2
@@ -306,4 +306,4 @@ SELECT list_transform([[2, 3], [4]], x -> list_transform([1], y -> x || [y]))
 query I
 SELECT list_transform([[2, 3], [4]], x -> list_transform(x, y -> x || [y]))
 ----
-[[[2, 3, 2], [2, 3, 3]], [[4, 4]]]
+[[[2, 3, 2], [2, 3, 3]], [[4, 4]]]

test/sql/window/test_ignore_nulls.test

@@ -26,6 +26,7 @@ SELECT
     ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	NULL
 1	1	NULL	614
@@ -44,6 +45,7 @@ SELECT
     ROWS BETWEEN 1 PRECEDING AND UNBOUNDED FOLLOWING
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	614
 1	1	NULL	614
@@ -62,6 +64,7 @@ SELECT
     ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	NULL
 1	1	NULL	NULL
@@ -79,6 +82,7 @@ SELECT
     ORDER BY id
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	639
 1	1	NULL	639
@@ -96,6 +100,7 @@ SELECT
     ORDER BY id
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	-1
 1	1	NULL	614
@@ -114,6 +119,7 @@ SELECT
     ORDER BY id
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	614
 1	1	NULL	NULL
@@ -135,6 +141,7 @@ SELECT
     ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	NULL
 1	1	NULL	614
@@ -153,6 +160,7 @@ SELECT
     ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	NULL
 1	1	NULL	614
@@ -171,6 +179,7 @@ SELECT
     ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	NULL
 1	1	NULL	NULL
@@ -188,6 +197,7 @@ SELECT
     ORDER BY id
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	NULL
 1	1	NULL	NULL
@@ -205,6 +215,7 @@ SELECT
     ORDER BY id
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	-1
 1	1	NULL	614
@@ -223,6 +234,7 @@ SELECT
     ORDER BY id
   ) AS last_order_id
 FROM issue2549
+ORDER BY ALL
 ----
 0	1	614	614
 1	1	NULL	NULL

test/sql/window/test_mad_window.test

@@ -98,7 +98,7 @@ NULL	NULL	0.333333
 query IIII
 SELECT r % 3 as p, r, n, mad(n) over (partition by r % 3 order by r)
 FROM (SELECT r, CASE r % 2 WHEN 0 THEN r ELSE NULL END AS n FROM mads) nulls
-ORDER BY 1
+ORDER BY 1, 2
 ----
 NULL	NULL	NULL	NULL
 NULL	NULL	NULL	NULL

test/sql/window/test_mode_window.test

@@ -2,6 +2,9 @@
 # description: Test MODE aggregate as a window function
 # group: [window]
 
+# Temporary fix until state issue resolved
+require vector_size 64
+
 statement ok
 SET default_null_order='nulls_first';
 
@@ -32,7 +35,9 @@ NULL	NULL	NULL	NULL
 1	9	3	1
 
 query III
-SELECT r, r//3, mode(r//3) over (order by r rows between 1 preceding and 1 following) FROM modes ORDER BY 1, 2
+SELECT r, r//3, mode(r//3) over (order by r rows between 1 preceding and 1 following) 
+FROM modes 
+ORDER BY ALL
 ----
 NULL	NULL	NULL
 NULL	NULL	NULL