re: UDF bad performance

This simple function should be eligible for inlining. You will need to
remove the BEGIN and END from the function definition and make sure it is
defined as DETERMINISTIC. A function that is inlined is rerwritten into
the query that uses it by the optimizer, removing the overhead of calling
the function completely.

Detailed information about inline functions (applies to both scalar and
table functions) can be found at the following link and in the SQL
Reference.

https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/IBM%20i%20Technology%20Updates/page/Improved%20Inlining%20support%20for%20SQL%20Scalar%20User%20Defined%20Functions%20(UDFs)

Sue Romano
IBM i SQL development

I have this UDF that returns an integer:
BEGIN
RETURN CEILING ( LENGTH * WIDTH * HEIGHT / 166 ) ;
END

Calls to this UDF take a lot longer than I expect (about 21x longer than

an index-based SELECT statement). I checked all the parameters, and the

data types match verbatim so there shouldn't be any implicit conversions.

Any suggestions?