rewrite TPCH Q21 with temp-tables

sample-queries-tpch/tpch_query21.sql

@@ -1,94 +1,36 @@
-drop view q21_tmp1_cached;
-drop view q21_tmp2_cached;
+-- explain
 
-create view q21_tmp1_cached as
-select
-	l_orderkey,
-	count(distinct l_suppkey) as count_suppkey,
-	max(l_suppkey) as max_suppkey
-from
-	lineitem
-where
-	l_orderkey is not null
-group by
-	l_orderkey;
+create temporary table l3 stored as orc as 
+select l_orderkey, count(distinct l_suppkey) as cntSupp
+from lineitem
+where l_receiptdate > l_commitdate and l_orderkey is not null
+group by l_orderkey
+having cntSupp = 1
+;
 
-create view q21_tmp2_cached as
-select
-	l_orderkey,
-	count(distinct l_suppkey) count_suppkey,
-	max(l_suppkey) as max_suppkey
+with location as (
+select supplier.* from supplier, nation where
+s_nationkey = n_nationkey and n_name = 'SAUDI ARABIA'
+)
+select s_name, count(*) as numwait
 from
-	lineitem
-where
-	l_receiptdate > l_commitdate
-	and l_orderkey is not null
-group by
-	l_orderkey;
-
-select
-	s_name,
-	count(1) as numwait
-from (
-	select s_name from (
-		select
-			s_name,
-			t2.l_orderkey,
-			l_suppkey,
-			count_suppkey,
-			max_suppkey
-		from
-			q21_tmp2_cached t2 right outer join (
-			select
-				s_name,
-				l_orderkey,
-				l_suppkey from (
-				select
-					s_name,
-					t1.l_orderkey,
-					l_suppkey,
-					count_suppkey,
-					max_suppkey
-				from
-					q21_tmp1_cached t1 join (
-						select
-							s_name,
-							l_orderkey,
-							l_suppkey
-						from
-							orders o join (
-							select
-								s_name,
-								l_orderkey,
-								l_suppkey
-							from
-								nation n join supplier s
-							on
-								s.s_nationkey = n.n_nationkey
-								and n.n_name = 'SAUDI ARABIA'
-								join lineitem l
-							on
-								s.s_suppkey = l.l_suppkey
-							where
-								l.l_receiptdate > l.l_commitdate
-								and l.l_orderkey is not null
-						) l1 on o.o_orderkey = l1.l_orderkey and o.o_orderstatus = 'F'
-					) l2 on l2.l_orderkey = t1.l_orderkey
-				) a
-			where
-				(count_suppkey > 1)
-				or ((count_suppkey=1)
-				and (l_suppkey <> max_suppkey))
-		) l3 on l3.l_orderkey = t2.l_orderkey
-	) b
-	where
-		(count_suppkey is null)
-		or ((count_suppkey=1)
-		and (l_suppkey = max_suppkey))
-) c
+(
+select li.l_suppkey, li.l_orderkey
+from lineitem li join orders o on li.l_orderkey = o.o_orderkey and
+                      o.o_orderstatus = 'F'
+     join
+     (
+     select l_orderkey, count(distinct l_suppkey) as cntSupp
+     from lineitem
+     group by l_orderkey
+     ) l2 on li.l_orderkey = l2.l_orderkey and 
+             li.l_receiptdate > li.l_commitdate and 
+             l2.cntSupp > 1
+) l1 join l3 on l1.l_orderkey = l3.l_orderkey
+ join location s on l1.l_suppkey = s.s_suppkey
 group by
-	s_name
+ s_name
 order by
-	numwait desc,
-	s_name 
+ numwait desc,
+ s_name
 limit 100;