Even though XML schema has been around for a decade, still many APIs reference a DTD in the XML documents sent back and fourth. Such is the OpenSRS API. DB2 requires an XML schema or a DTD to be registered before it will process XML documents that refer to an XML Schema or a DTD. The process of registering such XSROBJECTs with DB2 has changed in DB2 since version 8.

Solution

• register a DTD using the DB2 9.7 command line:
db2 CONNECT TO SAMLE
db2 REGISTER XSROBJECT 'dtd-file-name.dtd' FROM /path/to/dtd/file AS sample.dtd-name DTD

  If the command is successful, the output is
DB20000I The REGISTER XSROBJECT command completed successfully.

• Register a DTD from a Java program:
String schemaName = "SAMPLE";
String dtdName = "dtd-name";
String dtdFile = "dtd-file-name.dtd";
Reader fis = new FileReader(dtdFile);
byte[] contentDtd = FileIO.readerToString(fis).getBytes();
String registerProcQuery = "CALL SYSPROC.XSR_DTD (?,?,?,?,?)";
PreparedStatement registerProcStatement = conn.prepareCall(registerProcQuery);
registerProcStatement.setString(1, schemaName);
registerProcStatement.setString(2, dtdName);
registerProcStatement.setString(3, dtdFile);
registerProcStatement.setString(4, "PUBLIC ID");
registerProcStatement.setObject(5, contentDtd, java.sql.Types.BLOB);
registerProcStatement.execute();

  The FileIO class can be found in Java Cookbook, Second Edition

References

• DB2 9.7 Documentation: REGISTER XSROBJECT
• DB2 9.7 Documentation: XSR_DTD procedure
• Redbook with Media : DB2 Java Stored Procedures Learning by Example (IBM Redbook)
• Java Cookbook, Second Edition

• Using DB2 XQuery to extract data mining results stored as PMML: this article is a great introduction to XQuery and Predictive Model Markup Language (PMML), a language to describe data mining models and to enable the exchange of mining models between different data mining providers.
• 15 best practices for pureXML performance in DB2: this article has valuable performance optimization advice that goes beyond the regular performance advice already covered in DB2 and AIX tuning essentials for DB2 performance.