[DRILL-3101] Setting "slice_target" to 1 changes the order of the columns in a "select *" query with order by

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Fix Version/s: 1.0.0
• Component/s: Execution - Relational Operators
• Assignee: Chris Westin
• Reporter: Rahul Kumar Challapalli
• Created: 15/May/15 17:35
• Updated: 30/Oct/17 19:31
• Resolved: 15/May/15 20:02

Description

git.commit.id.abbrev=d8b1975

With Default Settings :

select * from region order by length(r_name);
+-------------+--------+-----------+
| r_regionkey | r_name | r_comment |
+-------------+--------+-----------+
| 2 | ASIA | ges. thinly even pinto beans ca |
| 0 | AFRICA | lar deposits. blithely final packages cajole. regular waters are final requests. regular accounts are according to  |
| 3 | EUROPE | ly final courts cajole furiously final excuse |
| 1 | AMERICA | hs use ironic, even requests. s |
| 4 | MIDDLE EAST | uickly special accounts cajole carefully blithely close requests. carefully final asymptotes haggle furiousl |

Now after setting the slice target to 1, the order of the columns changed

0: jdbc:drill:schema=dfs_eea> alter session set `planner.slice_target` = 1;
+-------+--------------------------------+
|  ok   |            summary             |
+-------+--------------------------------+
| true  | planner.slice_target updated.  |
+-------+--------------------------------+
1 row selected (0.11 seconds)
0: jdbc:drill:schema=dfs_eea> select * from region order by length(r_name);
+-----------+--------+-------------+
| r_comment | r_name | r_regionkey |
+-----------+--------+-------------+
| ges. thinly even pinto beans ca | ASIA | 2 |
| lar deposits. blithely final packages cajole. regular waters are final requests. regular accounts are according to  | AFRICA | 0 |
| ly final courts cajole furiously final excuse | EUROPE | 3 |
| hs use ironic, even requests. s | AMERICA | 1 |
| uickly special accounts cajole carefully blithely close requests. carefully final asymptotes haggle furiousl | MIDDLE EAST | 4 |
+-----------+--------+-------------+
5 rows selected (0.796 seconds)

This does not happen when we do not use an "order by" in query

Issue Links

• is duplicated by: DRILL-1499 Different column order could appear in the result set for a schema-less select * query, even there are no changing schemas.
• relates to: DRILL-5822 The query with "SELECT *" with "ORDER BY" clause and `planner.slice_target`=1 doesn't preserve column order