XML Data StorageXML Data Storage

Joe CarrollJoe Carroll

Russell GibbonsRussell Gibbons

AgendaAgenda

What is XMLWhat is XML

Storage of XMLStorage of XML

Benefits of XML DatabasesBenefits of XML Databases

Problems with XML DatabasesProblems with XML Databases

DiscussionDiscussion

What is XMLWhat is XML

““XML (Extensible Markup Language) is a XML (Extensible Markup Language) is a W3C initiative that allows information and W3C initiative that allows information and services to be encoded with meaningful services to be encoded with meaningful structure and semantics that computers structure and semantics that computers and humans can understand. XML is great and humans can understand. XML is great for information exchange, and can easily for information exchange, and can easily be extended to include user-specified and be extended to include user-specified and industry-specified tagsindustry-specified tags.” .” www.orafaq.com/glossary/faqglosx.htm  www.orafaq.com/glossary/faqglosx.htm 

Storage of XMLStorage of XML

CharacterCharacter

Relational (shredded)Relational (shredded)

Native XMLNative XML

CharacterCharacter

Storage optionsStorage options Large character fields in DBMSLarge character fields in DBMS Flat filesFlat files .xml files.xml files

Fast insert & retrievalFast insert & retrieval

Poor searchPoor search

RelationalRelational

Data still stored as characterData still stored as character

Portions of the data extracted into Portions of the data extracted into additional relational tablesadditional relational tables

Increased parse timeIncreased parse time

Increased search capabilitiesIncreased search capabilities

Native XMLNative XML

Exclusive XML DBMSExclusive XML DBMS SednaSedna TimberTimber

Integrated XML DBMSIntegrated XML DBMS DB2DB2 OracleOracle

Native XML Benefits Native XML Benefits

XML messages stored in their original XML messages stored in their original formatformat

Documents can be transformed straight Documents can be transformed straight from the database via XPath or XSLT.from the database via XPath or XSLT.

Increased search capabilities for Increased search capabilities for documents that must be stored as XML.documents that must be stored as XML.

Native XML ProblemsNative XML Problems

Same problems as hierarchical databasesSame problems as hierarchical databases Many-to-many relationshipsMany-to-many relationships Referential IntegrityReferential Integrity

Difficult to handle within legacy Difficult to handle within legacy applications.applications.

Increased CPU consumption.Increased CPU consumption.

DiscussionDiscussion

ReferencesReferences

[1] Shalaka Natu, John Mendonca, “Digital Asset Management [1] Shalaka Natu, John Mendonca, “Digital Asset Management Using A Native XML Database Implementation”, CITC4 ’03, October Using A Native XML Database Implementation”, CITC4 ’03, October 16-18, 2003, Lafayette, Indiana, USA.16-18, 2003, Lafayette, Indiana, USA.[2] Matthias Nicola, Jasmi John, “XML Parsing: A Threat to [2] Matthias Nicola, Jasmi John, “XML Parsing: A Threat to Database Performance”, CIKM ’03, November 3-8, 2003, New Database Performance”, CIKM ’03, November 3-8, 2003, New Orleans, Louisiana, USA.Orleans, Louisiana, USA.[3] Mattias Nicola, Bert van der Linden, “Native XML Support in [3] Mattias Nicola, Bert van der Linden, “Native XML Support in DB2 Universal Database”, Proceedings of the 31st VLDB DB2 Universal Database”, Proceedings of the 31st VLDB Conference, Trondheim, Norway, 2005.Conference, Trondheim, Norway, 2005.[4] “Native XML data store overview”, [4] “Native XML data store overview”, http://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.dbhttp://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.db2.udb.apdv.embed.doc/doc/c0022308.htm2.udb.apdv.embed.doc/doc/c0022308.htm[5] “Use XML databases to empower Java Web services”, [5] “Use XML databases to empower Java Web services”, http://www.javaworld.com/javaworld/jw-12-2004/jw-1206-xml.htmlhttp://www.javaworld.com/javaworld/jw-12-2004/jw-1206-xml.html