XML and Databases
Oluwasegun Adedugbe and Pavan Kurma
Faculty of Computing, Engineering and Technology,
Stafford, ST18 0AD
XML stands for eXtensible Markup Language
Widely used on the World Wide Web as a means of
communication between different types of web
It is a W3C (World Wide Web Consortium) standard
XML is a markup language, like HTML
XML primarily consists of tags, attributes and data
XML tags are not pre-defined like HTML
XML tags are user-defined
While HTML defines the layout for data, XML
describes the data
XML documents need to be well formed
Transporting, Storing and Sharing Data
Web-based feeds, such as RSS, jobs, weather
reports, stock updates, etc.
Strengths of XML
It is written in plain text format
It is platform independent, either hardware or
It works well with applications
It’s a W3C standard, which makes it universal
XML vs. RDMSs
XML does not support traditional elements of
relational databases such as triggers, indexes,
queries across multiple documents, etc.
XML will not be suitable for very large amounts of
data unlike relational databases
XML is file-based while relational databases are
Speed – Data retrieval could be relatively slow due
to verbose nature
Security – Data could be interrupted during
Scope – Limited scope in comparison to relational
Schemas are used to validate XML documents
A Schema defines the structure and data
constraints of an instance XML document
Examples are DTD (Document Type Definition),
XML Schema, etc.
Validators check an XML document against its
schema and determines if its valid or not
Examples of XML Validation tools are Core Filing,
W3C XML Validator, etc.
XML stores, transports and shares data. It’s data
storage capabilities is very limited in relation to
It is a very vital tool for communicating between
applications over networks
It’s use as a means of data storage should be for
small/medium-sized amount of data
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Wales, September 2010.
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