This appendix describes the restrictions associated with Oracle XML DB.
Replication – Oracle XML DB does not support replication of
Extending Resource Metadata Properties – You cannot extend the resource schema. However, you can set and access custom properties belonging to other namespaces, other than
XDBResource.xsd, using DOM operations on the
References Within Scalars – Oracle does not support references within a scalar,
XMLType, or LOB data column.
Thin JDBC Driver Not Supported by Some XMLType Functions – Methods
existsNode() work only with the thick JDBC driver. Not all
oracle.xdb.XMLType functions are supported by the thin JDBC driver. If you do not use
oracle.xdb.XMLType classes and the OCI driver, you could lose performance benefits.
NVARCHAR and NCHAR SQLTypes Not Supported – Oracle XML DB does not support
NCHAR as a
SQLType when registering an XML schema. In other words in the XML schema file (.xsd) you cannot specify that an element should be of type
NCHAR. Also, if you provide your own type you should not use these datatypes.
Identifier Length Limited to 4000 Characters – Oracle XML DB supports only XML identifiers that are 4000 characters long, or shorter.
64K Limit on Text Nodes and Attribute Values – Each text node or attribute value processed by Oracle XML DB is limited in size to 64K bytes.