[HIVE-5874] SubQuery: better error handling when SQ and Outer Query has the same table alias

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Harish Butani
• Created: 22/Nov/13 22:06
• Updated: 22/Nov/13 22:06

Description

The following query

select * from src where key in (select key from src where src.key > '1')

Gives the following message:

emanticException [Error 10249]: Line 1:58 Unsupported SubQuery Expression ''1'': SubQuery expression refers to Outer query expressions only.

Whereas the user is attempting to express an uncorrelated Subquery.
The ambiguity is because we attempt to resolve references against the Outer Query first. This is an implementation detail, see the Sub Query spec for details. For now it is better to disallow such SubQueries.