Help on Index creation on complex type

Question

Hi:
I have some problem in creating indexes on columns related to complex types.
Here is the steps performed
1)
I registered a schema with complextypes. The relevant part of the schema is as below:
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
     <xs:element name="ProteinEntry" type="ProteinEntryType"/>
     <xs:complexType name="ProteinEntryType">
          <xs:sequence>
               <xs:element name="header" type="headerType"/>
               <xs:element name="protein" type="proteinType"/>
               <xs:element name="organism" type="organismType"/>
          </xs:sequence>
          <xs:attribute name="id" type="xs:ID" use="required"/>
     </xs:complexType>
<xs:complexType name="organismType">
          <xs:sequence>
               <xs:element ref="source"/>
               <xs:element ref="common" minOccurs="0"/>
          </xs:sequence>
     </xs:complexType>
</xs:schema>
2) I registered this schema and I created a table "bioseq" of xmltype based on the schema.
3)when i do a describe of bioseq I get the following:
SQL> desc bioseq
Name Null? Type
TABLE of SYS.XMLTYPE(XMLSchema "http://accelrys.com/pir_edited_pir3.xsd" Element "ProteinEntry") STORAGE Object-relational TYPE "ProteinEntryType551_T"
4) when I do a describe of "ProteinEntryType551_T" I get the following :
SQL> desc "ProteinEntryType551_T";
"ProteinEntryType551_T" is NOT FINAL
Name Null? Type
SYS_XDBPD$ XDB.XDB$RAW_LIST_T
id VARCHAR2(4000)
organism organismType511_T
reference reference552_COLL
desc "organismType511_T" gives the following:
SYS_XDBPD$ XDB.XDB$RAW_LIST_T
source VARCHAR2(4000)
common VARCHAR2(4000)
What I want to do is create an index on the column source. I tried several syntaxes but failed. Is it possible to do this.
Sudhakar

Answer 1

Look at the Whitepaper on XML DB and the latest version of the XML DB Demo. It shows how to do this.