[IMPALA-6405] There is no error under Decimal v2 when there is an overflow when casting String to Decimal

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 2.11.0
• Fix Version/s: Impala 3.0, Impala 2.12.0
• Component/s: Backend
• Target Version: Impala 3.0
• Epic Color: ghx-label-2
• Assignee: Taras Bobrovytsky
• Reporter: Taras Bobrovytsky
• Created: 17/Jan/18 01:53
• Updated: 05/Apr/18 00:47
• Resolved: 07/Mar/18 00:46

Description

The following query correctly returns an error when Decimal v2 is enabled:

select cast(123 as decimal(2, 0));
ERROR: UDF ERROR: Decimal expression overflowed

However, this query incorrectly returns a NULL:

select cast("123" as decimal(2, 0))
+-----------------------------+
| cast('123' as decimal(2,0)) |
+-----------------------------+
| NULL                        |
+-----------------------------+