title: Why can't execute SCHEMA_NAME.PACKAGE_NAME.PROCEDURE, Oracle
body: <p>I have a schema A, Package B and Procedure C. B is in A schema and C is in B's Package Body.</p>
  
  <p>It works fine when I say:</p>
  
  <pre><code>Begin 
  Exec B.C;
  END;
  </code></pre>
  
  <p>But it throw an error when I say:</p>
  
  <pre><code>Begin
  Exec A.B.C;
  END;
  
  Error report:
  ORA-06550: line 2, column 12:
  PLS-00302: component 'B' must be declared
  ORA-06550: line 2, column 4:
  PL/SQL: Statement ignored
  </code></pre>
  
  <p>I log in as A so it's in A's schema.
  and 
  SELECT * FROM user_OBJECTS WHERE OBJECT_NAME = 'B';
  shows package and package body both valid.</p>