sql>conn scott/tiger
sql>grant select on emp to hr;

sql>conn hr/hr
sql>select * from [B]scott.emp[/B];
sql>create synonyn emp_scott for scott.emp;
sql>select * from emp_scott;

sql>create or replace function "name"
...
...
here use 1. synonym or table name with schema. 
like [b] emp_scott or scott.emp [/b]

end "name"