Error while registering the schema

Question

SQL> DECLARE
2 bibtex VARCHAR2(5000) :=
3 '<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
4 xmlns:xdb="http://xmlns.oracle.com/xdb">
5 <xs:annotation>
6 <xs:documentation>
7 This is a VERY simple XML Schema that will be used to validate th
btex.xml
8 </xs:documentation>
9 </xs:annotation>
10 <!-- The xml root element must be named BibTex -->
11 <xs:element name="BibTex">
12 <xs:complexType>
13 <xs:sequence>
14 <xs:element ref="Article" minOccurs="0" maxOccurs="unbounded"/>
15 <xs:element ref="InProceedings" minOccurs="0" maxOccurs="unbounded"/>
16 </xs:sequence>
17 </xs:complexType>
18 </xs:element>
19 <xs:element name="Article">
20 <xs:complexType>
21 <xs:sequence>
22 <xs:element ref="Authors"/>
23 <xs:element ref="Title"/>
24 <xs:element ref="Journal"/>
25 <xs:element ref="Year"/>
26 <xs:element ref="Volume"/>
27 <xs:element ref="Pages"/>
28 <xs:element ref="Number"/>
29 <xs:element ref="Month"/>
30 <xs:element ref="DOI"/>
31 <xs:element ref="Owner"/>
32 <xs:element ref="TimeStamp"/>
33 </xs:sequence>
34 <xs:attribute name="Key" type="xsd:string" use="required"/>
35 </xs:complexType>
36 </xs:element>
37 <xs:element name="InProceedings">
38 <xs:complexType>
39 <xs:sequence>
40 <xs:element ref="Authors"/>
41 <xs:element ref="Title"/>
42 <xs:element ref="BookTitle"/>
43 <xs:element ref="Year"/>
44 <xs:element ref="Pages"/>
45 <xs:element ref="Month"/>
46 <xs:element ref="DOI"/>
47 <xs:element ref="Volume" minOccurs="0"/>
48 <xs:element ref="Owner"/>
49 <xs:element ref="TimeStamp"/>
50 </xs:sequence>
51 <xs:attribute name="Key" type="xs:string" use="required"/>
52 </xs:complexType>
53 </xs:element>
54 <xs:element name="Authors">
55 <xs:complexType>
56 <xs:sequence>
57 <xs:element ref="Author" minOccurs="1" maxOccurs="unbounded"/>
58 </xs:sequence>
59 </xs:complexType>
60 </xs:element>
61 <xs:element name="Author">
62 <xs:complexType>
63 <xs:sequence>
64 <xs:element name="LastName" type="xs:string"/>
65 <xs:element name="Initials" type="xs:string"/>
66 </xs:sequence>
67 </xs:complexType>
68 </xs:element>
69 <xs:element name="Title" type="xs:string"/>
70 <xs:element name="Year">
71 <xs:simpleType>
72 <xs:restriction base="xs:integer">
73 <!--
74 Constrain the year to 4 digits, 0-9 each. No other characters
75 -->
76 <xs:pattern value="[0-9]{4}"/>
77 </xs:restriction>
78 </xs:simpleType>
79 </xs:element>
80 <xs:element name="Pages" type="xs:string"/>
81 <xs:element name="Month" type="xs:string"/>
82 <xs:element name="DOI" type="xs:string"/>
83 <xs:element name="Owner" type="xs:string"/>
84 <xs:element name="TimeStamp" type="xs:date"/>
85 <xs:element name="BookTitle" type="xs:string"/>
86 <xs:element name="Journal" type="xs:string"/>
87 <xs:element name="Volume" type="xs:string"/>
88 <xs:element name="Number" type="xs:string"/>
89 </xs:schema>';
90 BEGIN
91 DBMS_XMLSCHEMA.RegisterSchema('bibtex.xsd', bibtex);
92 END;
93 /
DECLARE
ERROR at line 1:
ORA-30940: Cannot resolve prefix 'xsd' for QName node 'type'
ORA-06512: at "XDB.DBMS_XMLSCHEMA_INT", line 3
ORA-06512: at "XDB.DBMS_XMLSCHEMA", line 14
ORA-06512: at line 91

Answer 1

<xs:attribute name="Key" type="xsd:string" use="required"/>there is no namespace for prefix xsd!
Look like a typo, change it to "xs:string"