[DRILL-568] set NO_EXCHANGES=true did not have any effect

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.4.0
• Assignee: Unassigned
• Reporter: Chun Chang
• Created: 25/Apr/14 02:12
• Updated: 10/Mar/17 01:19
• Resolved: 09/Jun/14 05:34

Description

0: jdbc:drill:schema=dfs> alter session set NO_EXCHANGES=true;
----------------------+

ok

summary

----------------------+

true	disabled exchanges.

----------------------+
1 row selected (0.016 seconds)

The explain plan for still shows we hash to random exchange:
0: jdbc:drill:schema=dfs> explain plan for select cast(customer.country as varchar(20)) as c0 from customer as customer where UPPER(cast(customer.country as varchar(20))) = UPPER('USA') group by cast(customer.country as varchar(20));
----------------------+

text

json

----------------------+
....

},

{ "pop" : "hash-to-random-exchange", "@id" : 5, "child" : 4, "expr" : "hash(`c0`) " }

, {