--! qt:dataset:src
set hive.mapred.mode=nonstrict;
set hive.optimize.cte.materialize.threshold=1;
set hive.optimize.cte.materialize.full.aggregate.only=false;
set hive.explain.user=true;

explain
with q1 as ( select key from src where key = '5')
select *
from q1
;

with q1 as ( select key from src where key = '5')
select *
from q1
;

-- in subquery
explain
with q1 as ( select key from src where key = '5')
select * from (select key from q1) a;

with q1 as ( select key from src where key = '5')
select * from (select key from q1) a;

-- chaining
explain
with q1 as ( select key from q2 where key = '5'),
q2 as ( select key from src where key = '5')
select * from (select key from q1) a;

with q1 as ( select key from q2 where key = '5'),
q2 as ( select key from src where key = '5')
select * from (select key from q1) a;