Major project

PREFIX- BASED LABELLING

SCHEME FOR XML

XML

XML documents have a hierarchical structure and can

conceptually be interpreted as a tree structure, called an XML tree.

XML is becoming the new standard for the exchange and publishing of data over the Internet

Labelling schemes for xml

Need for labelling:

Labeling schemes have been developed to optimize query retrieval,

since they provide a quick way to determine the type of relationships that are present among the nodes.

The main novelty of Labelling the tree is that it allows people with

limited IT-skills to query and explore one (or multiple) data sources

without prior knowledge about the schema, structure, vocabulary, or

any technical details of these sources.

Prefix labelling schemes:

Prefix –based schemes directly encode the father of a node in a tree,

as a prefix of its label.

Existing/proposed prefix based schemes: dewey encoding

Cohen et all

Lsdx

Ordpath

Kheing et all

performance of various schemes

We compare these schemes on the basis of:

Robustness

Time to process query

Tools/techniques used

Sax parser

Netbeans ide

Tools/techniques used

Sax parser

Netbeans ide

Requirements

Functional Requirements

Graphical User interface which the user

Provide accessibility to the application even to people with limited IT-skills to perform and generate a tree.

It should be able to extract the file and send it to sax Parser efficiently.

Non Functional Requirements

It must have scalability i.e. the xml file can be large enough with numerous amounts of attributes in it and should be parsed efficiently.

Reliability-the ability of the system to behave consistently in a user-acceptable manner when operating within the environment for which the system was intended

Usability-finding usability problems in UI design, making recommendations for fixing them, and improving UI design.

8Dewey - Structure

Each node is assigned a label that represents the path from the document’s root to the node.

Each component of the label represents the local order of an ancestor node.

Nodes with the same number of delimiters (“.”) in their label are in the same level.

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Dewey ID(Prefix) based Labeling

10LSDX - StructureDuong et al. - 2005

Labeling Scheme for Dynamic Xml dataAllow updates without re-labeling other nodesCombine numbers and letters to label each treeFor a node X, its label is:level(X)parent(X).positionalIdentifier(X)

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insert before operation

Xml query processing:

XQuery is a query and functional programming language that is

designed to query and transform collections of structured and

unstructured data, usually in the form of XML, text and with vendor-specific extensions for other data formats (JSON, binary, etc.). The

language is developed by the XML Query working group of

the W3C