Data Normalization - Information Systems Reengineering, Integration and Normalization - page 351

XML document of many-to-many cardinality

XML document with data Redundancy free normalized XML

document redundancy

<xs:element name="d">
<xs:complexType>
<xs:attribute name="x"
type="xs:string" />
</xs:complexType>
</xs:element>
<xs:element name="e">
<xs:complexType>
<xs:attribute name="y"
type="xs:string" />

<xs:element name="d">
<xs:complexType>
<xs:attribute name="x"
type="xs:string" />
<xs:attribute name="d"
type="xs:string" />
</xs:complexType>
<xs:key name="dKey">
<xs:selector xpath="d" />
<xs:field xpath="@d" />

</xs:complexType>
</xs:element>
<xs:element name="R">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs=
"unbounded" name="R1">
<xs:complexType>
<xs:sequence>
<xs:element
ref="d" />
<xs:element
ref="e" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>

</xs:key>
</xs:element>
<xs:element name="e">
<xs:complexType>
<xs:attribute name="y"
type="xs:string" />
<xs:attribute name="e" />
</xs:complexType>
<xs:key name="eKey">
<xs:selector xpath="e" />
<xs:field xpath="@e" />
</xs:key>
</xs:element>
<xs:element name="d_ref">
<xs:complexType>
<xs:attribute name="d"
type="xs:string" />
</xs:complexType>
<xs:keyref name="d_refTodKey"
refer="dKey">
<xs:selector xpath="d_ref" />
<xs:field xpath="@d" />
</xs:keyref>
</xs:element>
<xs:element name="e_ref">
<xs:complexType>
<xs:attribute name="e"
type="xs:string" />
</xs:complexType>