Extending the Resource XML Schema XDBResource.xsd

Question

Hi,
Is anybody could share an expirience about extending
the Resource XML Schema XDBResource.xsd ?
I want to use XML DB as document repository.
I want to use some application parameters (for
example document varchar id and so on) as resource
properties. I read from Oracle documentation, that
one way is to extend the Resource XML Schema XDBResource.xsd.
Users will put documents using WebDAV, so new schema
should be used default instead of XDBResource.xsd.
Is it possible ?
Thanks in advance
Viacheslav

Answer 1

Thos is an error in the documentation. Extending the Resource Schema is not currently supported. We are considering this for a future release of the product. XML DB does allow small amounts of user defined meta data to be added to a Resource.....
For Instance Given the following package
create or replace package xdb_namespaces
as
RESOURCE_NAMESPACE constant VARCHAR2(128) := 'http://xmlns.oracle.com/xdb/XDBResource.xsd';
METADATA_NAMESPACE constant VARCHAR2(128) := 'http://xmlns.oracle.com/xdb/userMetaData';
RESOURCE_PREFIX_R constant VARCHAR2(128) := 'xmlns:r="' || RESOURCE_NAMESPACE || '"';
METADATA_PREFIX_M constant VARCHAR2(128) := 'xmlns:m="' || METADATA_NAMESPACE || '"';
end;
select * from all_errors where owner = 'XDB'
create or replace public synonym XDB_NAMESPACES for XDB_NAMESPACES
grant execute on XDB_NAMESPACES to public
The following procedure can add metadata to the ANY defined by the current resource Schema
procedure addUserMetaDataNode(OID varchar2)
as
metadata_xml XMLTYPE := XMLTYPE('<m:UserMetaData ' || XDB_NAMESPACES.METADATA_PREFIX_M || '/>');
begin
update /*+ NO_TRIGGER */ XDB.XDB$RESOURCE r
set r.xmldata.RESEXTRA = metadata_xml.getClobVal()
where sys_nc_oid$ = hextoraw(OID)
and existsNode
object_value,
'/r:Resource/r:Contents',
XDB_NAMESPACES.RESOURCE_PREFIX_R
) = 1
and existsNode
object_value,
'/r:Resource/m:UserMetaData',
XDB_NAMESPACES.RESOURCE_PREFIX_R || ' ' || XDB_NAMESPACES.METADATA_PREFIX_M
) = 0;
end;
Note that this is not a SUPPORTED method of doing this.. Once the UserMetaDataNode has been added additional metadata can be added using updateXML with an XPATH that targets the UserMetaData node.
A Future release of XML DB will provide a facitlity to attach a row in a schema based XML table, containing user defined meta data to a resoure, in the same way that the defaultTable mechanisim allows the content of a resource to be stored in an XMLType table.