title: Add FOREIGN KEY CONSTRAINT between different owners
body: <p>I'm logged on a Oracle XE instance as SYSTEM user. When I try to run an script that create users, tables and constraints I get an <code>ORA-01031</code> error. The script is as follows:</p>
  
  <pre class="lang-sql prettyprint-override"><code>CREATE USER AA IDENTIFIED BY AA DEFAULT TABLESPACE users TEMPORARY TABLESPACE temp;
  CREATE USER BB IDENTIFIED BY BB DEFAULT TABLESPACE users TEMPORARY TABLESPACE temp;
  GRANT ALL PRIVILEGES TO AA WITH ADMIN OPTION;
  GRANT ALL PRIVILEGES TO BB WITH ADMIN OPTION;
  ...
  CREATE TABLE ...
  CREATE INDEX ...
  ...
  ALTER TABLE "BB"."B_TABLE" ADD CONSTRAINT "FK_BB_AA" FOREIGN KEY ("AA_ID")
    REFERENCES "AA"."A_TABLE" ("ID") ENABLE; -- this line report the error
  </code></pre>
  
  <p>It's not possible to to add this constraint on Oracle XE?</p>