[DRILL-6378] MajorType passed into UDF with FieldReader has unset prec, scale for DECIMAL

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.13.0
• Assignee: Vova Vysotskyi
• Reporter: Paul Rogers
• Created: 02/May/18 06:00
• Updated: 04/May/18 22:43
• Resolved: 04/May/18 18:59

Description

UDFs allow passing in a generic FieldReader such as for the typeof function. I tried to modify the new sqlTypeOf() function to include the DECIMAL precision and scale, something like: DECIMAL(9, 2).

But, the MajorType associated with the FieldReader has these values as 0. Not sure if it is because the DECIMAL is the result of a cast, or if there is a deeper bug.

Query:

ALTER SESSION SET `planner.enable_decimal_data_type` = true;

SELECT sqlTypeof(CAST(a AS DECIMAL)) FROM (VALUES (1)) AS T(a);

Debug information for the MajorType

type	TypeProtos$MajorType  (id=151)	
precision_	0	
scale_	0	

This bug is not simply a nuisance for formatting. The precision and scale are required to make sense of any DECIMAL values that the function wants to process: without these values, the function does not know the meaning of the DECIMAL data.

Once this bug is fixed, reenable the type suffix code in UnionFunctions.extendType().

Issue Links

• relates to: DRILL-6094 Decimal data type enhancements