Database Software

This is my version of Oracle:

BANNER
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Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
PL/SQL Release 11.2.0.2.0 - Production
CORE    11.2.0.2.0      Production
TNS for Solaris: Version 11.2.0.2.0 - Production
NLSRTL Version 11.2.0.2.0 - Production

I have create an Oracle User, called "AdvSearch", that have a number of folders in Xdb with a root folder of "/AdvSearch" for a development effort. Just for development, I have another Oracle User, "TEST_LEGALSERVICES" that I want full read and write to the files and folders under the cited root. I can't seem to grant access to the second User. Based on my reading, I tried this against the acl created for Advsearch:

DECLARE
   Dummy_Nr     PLS_INTEGER;
   Ace_Tx       VARCHAR2(2000);
   Ace_Xml      XMLType;
   AclPath_Tx   VARCHAR2(2000) := '/sys/acls/ADVSEARCH/ADVSEARCH_acl.xml';
 BEGIN
   Ace_Tx   := '<ace xmlns="http://xmlns.oracle.com/xdb/acl.xsd"
                     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                     xsi:schemaLocation="http://xmlns.oracle.com/xdb/acl.xsd
                                         http://xmlns.oracle.com/xdb/acl.xsd
                                         DAV:http://xmlns.oracle.com/xdb/dav.xsd">
                  <principal>TEST_LEGALSERVICES</principal>
                  <grant>true</grant>
                  <privilege><all/></privilege>
                </ace>';
   Ace_Xml  := XMLType.createXML(Ace_Tx);
   Dummy_Nr := DBMS_XDB.changePrivileges(AclPath_Tx, Ace_Xml);
 END;
 /

This code ran, but when I examine the file under AclPath_Tx, I can see that that xml node was not created. So when I run this query against one level up from the root, I get this message:

ELSDV03> SELECT DBMS_XDB.GETPRIVILEGES('/AdvSearch/Repository') AS Rights FROM Dual;
ERROR:
ORA-31050: Access denied
ORA-06512: at "XDB.DBMS_XDB", line 422


no rows selected

I am not sure if this is relevant, but this is my acl after the change privilege has been run:

select XdbUriType('/sys/acls/ADVSEARCH/ADVSEARCH_acl.xml').GetXml() as doc FROM Dual;

DOC
------------------------------------------------------------------------------------------------------------------------
<acl description="Protected:Readable by PUBLIC and all privileges to OWNER" xmlns="http://xmlns.oracle.com/xdb/acl.xsd"
xmlns:dav="DAV:" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.oracle.com/xdb/a
cl.xsd                           http://xmlns.oracle.com/xdb/acl.xsd" shared="false">
  <ace>
    <grant>true</grant>
    <principal>dav:owner</principal>
    <privilege>
      <all/>
    </privilege>
  </ace>
  <ace>
    <grant>true</grant>
    <principal>XDBADMIN</principal>
    <privilege>
      <all/>
    </privilege>
  </ace>
  <ace>
    <grant>true</grant>
    <principal>PUBLIC</principal>
    <privilege>
      <read-properties/>
      <read-contents/>
      <read-acl/>
      <resolve/>
    </privilege>
  </ace>
  <ace>
    <grant>true</grant>
    <principal>ADVSEARCH</principal>
    <privilege>
      <all/>
    </privilege>
  </ace>
</acl>


1 row selected.

I guess I am missing a step or otherwise doing something wrong. Just how can I grant access to all the files and folders under /AdvSearch to Test_LegalServices? Another related question, does there have to two ACL files for the two Users, or can just one work for one set of folders in Xdb?

Thank you.