Question

Related to this question, I decided to check the UDFs in my data warehouse (which should largely have been deterministic), and I found several which aren’t which should be.

For instance:

CREATE FUNCTION [udf_YearFromDataDtID] (     @DATA_DT_ID int ) RETURNS int AS BEGIN     RETURN @DATA_DT_ID / 10000 END 

Shows up in this query:

SELECT  ROUTINE_NAME FROM    INFORMATION_SCHEMA.ROUTINES WHERE   IS_DETERMINISTIC = 'NO'         AND ROUTINE_TYPE = 'FUNCTION' ORDER BY ROUTINE_NAME 

Why is this?

Answer 1

Yikes – apparently, it REQUIRES SCHEMABINDING to be specified other wise it could cause performance problems

ALTER FUNCTION [udf_YearFromDataDtID] (     @DATA_DT_ID int ) RETURNS int WITH SCHEMABINDING AS BEGIN     RETURN @DATA_DT_ID / 10000 END 

Looks like I could be getting some performance boosts by fixing these. Nice.