[DRILL-2271] count(distinct ) against SystemTablePlugin will hit plan serialization/deserialization issue when executed in distributed mode.

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Assignee: Unassigned
• Reporter: Jinfeng Ni
• Created: 19/Feb/15 19:34
• Updated: 19/Feb/15 19:56
• Resolved: 19/Feb/15 19:56

Description

The following query run fine in single node.

select count(distinct name) as cnt from `sys`.`options`;

However, if change the slice_target =1 and make it run in distributed mode, it hit error :

alter session set `planner.slice_target` = 1;
+------------+------------+
|     ok     |  summary   |
+------------+------------+
| true       | planner.slice_target updated. |
+------------+------------+

select count(distinct name) as cnt from `sys`.`options`;
Query failed: RemoteRpcException: Failure while trying to start remote fragment, No suitable constructor found for type [simple type, class org.apache.drill.exec.store.sys.SystemTablePlugin]: can not instantiate from JSON object (need to add/enable type information?)

Seems the serialization/deserialization of the plan for SystemTablePlugin does not work correctly.

Issue Links

• is duplicated by: DRILL-2246 select from sys.options fails in a weird way when slice_target=1