IBM DB2 UD &IBM DB2 UD &XML ExtenderXML ExtenderIBM DB2 UD &IBM DB2 UD &XML ExtenderXML Extender

AstroGrid Project AstroGrid Project Registry GroupRegistry GroupPedro ContrerasPedro Contreras

14 August 200314 August 2003

OverviewOverviewInstallation & Requirement

XML Extender

How DB2 and XML Extender work together

Storages and access methods

XML column methodXML collection method

Document Access Definition (DAD) file  

Working with XML ExtenderPlanning how to store the documentSteps to enable XML extender for XML document

Mapping a DAD file: an example    

Installation & Requirement

Can be installed as part of DB2 Universal Database 8.1 Or can be installed later

Requirement

- DB2ADM authority- Bind the XML Extender to your DB2 UDB database

XML Extender

- Stores and access XML documents

- Generates XML documents from an existent Database

- Inserts row into relational tables from XML documents

- It provides new data types, functions and store procedure to manage XML data in DB2

How DB2 and XML Extender work together

- Administration tools to help with the integration of XML Data with DB2- XML Extender wizard- dxxadm command line - XML Extender Store procedures

- Store and access methods for XML data within the database

- DTD (or schemas) used to validate XML data

- A mapping file called Document Access Definition (DAD), used to map XML documents into relational data

Storages and access methods

XML Extenders provides two different methods for integrating XML documents withDB2 data structures: XML columns and XML collections. These methods aredifferent but can be used in the same application.

XML column methodIt stores intact XML documents in DB2. This method works well for archiving documents. The documents are inserted into columns enabled for XML that can be updated, retrieved and searched.

XML collection methodThis method map XML document structure to DB2 tables. So, it can either compose XML documents from existent DB2 data, or decompose XML documents into DB2 tables.This method is good when the contents of XML documents are frequentlyupdated

Document Access Definition (DAD) file

It defines the locations of important files like DTD or schemas, and specifies how the XML document structure is related to DB2 data.

It also defines the access and storage method used in the application.

In short, the DAD file is an XML document that maps the XML structure to the DB2 table.

Planning how to store the document

- Understand the structure of XML document

- Identify the XML user-defined type in which you will store the XML document

- Identify XML elements that will be frequently search. The content of

these can be store in side tables and indexed to improve performance

Steps to enable XML extender for XML documents- Choose one method of mapping: XML column or XML collection

- Enable the DB to work with XML files: “dxxadm enable_db db_name”

- Store the DTD into DB2: can be done by command line or the GUI

- Create a DAD file

- Create and enable the columns to store the XML document

Working with XML Extender

<?xml?><!DOCTYPE..>

< element > . .</element >

. .<Xcollection> <table> <column> </table> . .<Xcollection>

XML Document DAD file

DB2

Mapping a DAD file

serviceMetadataConcept

interfaceMetadatacapabilitiesMetadata

serviceRestriction

serviceStandardUri

serviceStandardUrl

serviceRestrictionSpatial

serviceMaxNrows

serviceMaxImageSize

serviceMSR

serviceHTTPResultType

serviceHTTPResult

serviceInterfaceUrl

serviceBaseUrl

service.xml

Mapping a DAD file

serviceMetadataConcept

interfaceMetadatacapabilitiesMetadata

serviceRestriction

serviceStandardUri

serviceStandardUrl

serviceRestrictionSpatial

serviceMaxNrows

serviceMaxImageSize

serviceMSR

serviceHTTPResultType

serviceHTTPResult

serviceInterfaceUrl

serviceBaseUrl

StandardUri

StandardUr

MSR

MaxImageSize

httpResultType

interfaceUrl

baseUrl

MaxNrows

service.xml mapped to DB

Name of column in DB2 table

Mapping a DAD file

XML Extender Administrator LaunchPad

COM.ibm.db2.jdbc.net.DB2.Driver (network connection)

jdbd:db2://[host]:[port]//[database] (network connection)

XML Extender Administrator LaunchPad

Create DAD file automatically

Creating a DAD file with XML Administrator Wizard

Creating a DAD file with XML Administrator Wizard

Creating a DAD file with XML Administrator Wizard

<?xml version="1.0"?><!DOCTYPE DAD SYSTEM "D:\AstroGrid\xml\db2Test\dad.dtd"><DAD> <dtdid>D:\AstroGrid\xml\db2Test\service.dtd</dtdid> <validation>YES</validation>

<Xcolumn> <table name="service"> <column name="maxNrows" type="varchar()" path="/serviceMetadataConcept/capabilitiesMetadataserviceRestriction/serviceMaxNrows" multi_occurrence="NO"/> <column name="restrictionSpatial" type="varchar()" path="/serviceMetadataConcept/capabilitiesMetadata/serviceRestriction/serviceRestrictionSpatial" multi_occurrence="NO"/> <column name="MSR" type="varchar()" path="/serviceMetadataConcept/capabilitiesMetadata/serviceRestriction/serviceRestrictionSpatial/serviceMSR" multi_occurrence="NO"/> . . . </table> </Xcolumn></DAD>

Creating a DAD file with XML Administrator Wizard

DB2 Enabling XML capabilities in DB2

<?xml?><!DOCTYPE..>

< element > . .</element >

. .<Xcollection> <table> <column> </table> . .<Xcollection>

XML Document DAD file

DB2

Next step is enable DB2 to work with XML documents:depends of the method (column or collection) how to do it.Could be command line or DB2 XML Extender Wizard.

XML Column

XML Collection

SQL mappinguses SQL select statement todefines DB2 tables and condition

RDB_node mappinguses X-Path based database node

Compose XMLDB2 to XML

Decompose XMLXML to DB2

Store procedure:

dxxGenXML()

dxxGenClob()

dxxRetrieveXML()

dxxRetrieveXMLClob()

dxxShredXML

dxxInsertXML

XML Extender methods

Next steps

Map Schema files

Use java and store procedure to decompose XML documents