Redshift udf_sql1.sql

create or replace function udf_sql_bignum (float, float)
 returns float
stable
as $$
 select case when $1 > $2 then $1
 else $2
 end
$$ language sql;

--You can just call UDF as if you are calling built-in functions:

training=# select udf_sql_bignum(10.3,100.2); 
 udf_sql_bignum 
---------------- 
 100.2 
(1 row)