Function not found when package name exists with same name as schema name

Question

Hi all, any help would be appreciated :)
I found an issue with pl/sql resolving a functions location when the db has a package name with the same as the db schema name.
My example:
-- arbitrary test function, not in any package
create or replace FUNCTION testFunc
     inTest     IN VARCHAR2
RETURN VARCHAR2
AS
BEGIN
RETURN 'a';
END;
-- There is a package called "FM" with functions that are not referenced or used in this example and the db schema is "FM".
-- The following PL/SQL fails with the message: "ORA-00904: "FM"."TESTFUNC": invalid identifier"
select cursor (select testFunc('a') from dual) from dual;
-- The following PL/SQL works:
select * from (select testFunc('a') from dual);
As mentioned the function testFunc is NOT in the FM package. This issue does not happen when I remove the FM package. So it seems like there is an issue with cursors calling functions when there exists any package with the same name as the db schema.
Can anyone tell me why this happens and also what I can add to force the function that is not in any package to be referenced (without Oracle trying to look in the FM package)?
DB: Oracle 11.2.0.2
thanks!
Paul

Answer 1

Hi Paul,
In general I would not advice to have schema and objects with the same name.
Here is what documentation is saying here: How Name Resolution Differs in PL/SQL and SQL
PL/SQL uses the same name-resolution rules as SQL when the PL/SQL compiler processes a SQL statement, such as a DML statement. For example, for a name such as HR.JOBS, SQL matches objects in the HR schema first, then packages, types, tables, and views in the current schema.
PL/SQL uses a different order to resolve names in PL/SQL statements such as assignments and subprogram calls. In the case of a name HR.JOBS, PL/SQL searches first for packages, types, tables, and views named HR in the current schema, then for objects in the HR schema.As you can see above when using PL/SQL for your case Oracle searches first for packages, types, tables, and views named FM in the current schema, then for objects in the FM schema.
And because a package FM is found it is raising an error due to the fact that the procedure could not be found in that package.
I hope this clarify.
Regards.
Al