[DRILL-5554] Wrong error type for "SELECT a" from a CSV file without headers

• Type: Bug
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Fix Version/s: 1.17.0
• Assignee: Unassigned
• Reporter: Paul Rogers
• Created: 29/May/17 23:27
• Updated: 25/Jun/19 13:31
• Resolved: 25/Jun/19 13:31

Description

Create a CSV file without headers:

10,foo,bar

Use a CSV storage plugin configured to not skip the first line and not read headers.

Then, issue the following query:

SELECT a FROM `dfs.data.example.csv`

The result is correct: an error:

org.apache.drill.common.exceptions.UserRemoteException: 
DATA_READ ERROR: Selected column 'a' must have name 'columns' or must be plain '*'

But, the type of error is wrong. This is not a data read error: the file read just fine. The problem is a semantic error: a query form that is not compatible wth the storage plugin.

Suggest using UserException.unsupportedError() instead since the user is asking the plugin to do something that the plugin does not support.