[DRILL-7237] IllegalStateException in aggregation function 'single_value' when there is a varchar datatype in the subquery results

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.14.0, 1.15.0
• Fix Version/s: 1.17.0
• Labels: ready-to-commit
• Assignee: Vova Vysotskyi
• Reporter: Denys Ordynskiy
• Reviewer: Bohdan Kazydub
• Created: 03/May/19 19:38
• Updated: 10/May/19 22:46
• Resolved: 10/May/19 22:46

Description

Description:
The following issue can be reproduced on the fix for the DRILL-7050.

For the query with > 1 row in subquery results where the data type of these results is not varchar:

SELECT
  e.full_name,
  (
    SELECT
      ine.employee_id
    FROM
      cp.`employee.json` ine
    WHERE
      ine.position_id = e.position_id
  ) as empl_id
FROM
  cp.`employee.json` e
LIMIT 20

We have the following correct and informative error:

Query Failed: An Error Occurred
org.apache.drill.common.exceptions.UserRemoteException: FUNCTION ERROR: Input for single_value function has more than one row Fragment 0:0 [Error Id: b770098f-b1c7-4647-9f41-9e986a0e47b7 on maprhost:31010]

But when in the result set of the subquery we have a varchar data type:

SELECT
  e.full_name,
  (
    SELECT
      ine.first_name
    FROM
      cp.`employee.json` ine
    WHERE
      ine.position_id = e.position_id
  ) as empl_id
FROM
  cp.`employee.json` e
LIMIT 20

Actual result:
Drill throws the following error:

org.apache.drill.common.exceptions.UserRemoteException: SYSTEM ERROR: IllegalStateException: Workspace variable 'value' in aggregation function 'single_value' is not allowed to have variable length type. Fragment 0:0 Please, refer to logs for more information. [Error Id: 32325ba9-d2b3-4216-acf6-8e80dfe4a56a on maprhost:31010]

Log file is in the attachment "drillbit.log"

Expected result:
Drill should return the same informative error to any of a data types in the subquery result set.

Issue Links

• links to: GitHub Pull Request #1782