Gautam Kowshik created HIVE-10996:
-------------------------------------

             Summary: Aggregation / Projection over Multi-Join Inner Query 
producing incorrect results
                 Key: HIVE-10996
                 URL: https://issues.apache.org/jira/browse/HIVE-10996
             Project: Hive
          Issue Type: Bug
          Components: Hive
    Affects Versions: 1.2.0, 1.0.0, 1.1.0
            Reporter: Gautam Kowshik
            Priority: Minor


We'v run this issue in Hive 1.1.0


The following query produces no results:


select s
from (
  select last.*, action.st2, action.n
  from (
    select purchase.s, purchase.timestamp, max (mevt.timestamp) as 
last_stage_timestamp
    from (select * from purchase_history) purchase
    join (select * from cart_history) mevt
    on purchase.s = mevt.s
    where purchase.timestamp > mevt.timestamp
    group by purchase.s, purchase.timestamp
  ) last
  join (select * from events) action
  on last.s = action.s and last.last_stage_timestamp = action.timestamp
) list;



While this one does produce results :

select *
from (
  select last.*, action.st2, action.n
  from (
    select purchase.s, purchase.timestamp, max (mevt.timestamp) as 
last_stage_timestamp
    from (select * from purchase_history) purchase
    join (select * from cart_history) mevt
    on purchase.s = mevt.s
    where purchase.timestamp > mevt.timestamp
    group by purchase.s, purchase.timestamp
  ) last
  join (select * from events) action
  on last.s = action.s and last.last_stage_timestamp = action.timestamp
) list;
1       21      20      Bob     1234
1       31      30      Bob     1234
3       51      50      Jeff    1234

The setup to test this is:
create table purchase_history (s string, product string, price double, 
timestamp int);
insert into purchase_history values ('1', 'Belt', 20.00, 21);
insert into purchase_history values ('1', 'Socks', 3.50, 31);
insert into purchase_history values ('3', 'Belt', 20.00, 51);
insert into purchase_history values ('4', 'Shirt', 15.50, 59);

create table cart_history (s string, cart_id int, timestamp int);
insert into cart_history values ('1', 1, 10);
insert into cart_history values ('1', 2, 20);
insert into cart_history values ('1', 3, 30);
insert into cart_history values ('1', 4, 40);
insert into cart_history values ('3', 5, 50);
insert into cart_history values ('4', 6, 60);

create table events (s string, st2 string, n int, timestamp int);
insert into events values ('1', 'Bob', 1234, 20);
insert into events values ('1', 'Bob', 1234, 30);
insert into events values ('1', 'Bob', 1234, 25);
insert into events values ('2', 'Sam', 1234, 30);
insert into events values ('3', 'Jeff', 1234, 50);
insert into events values ('4', 'Ted', 1234, 60);


I realize select * and select s are not all that interesting in this context 
but what lead us to this issue was select count(distinct s) was not returning 
results. The above queries are the simplified queries that produce the issue. 

I will note that if I convert the inner join to a table and select from that 
the issue does not appear.




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