XML Data Compression

[tosatish]

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Greg Leighton, Jim Diamond, Tomasz M ldner
February 18, 2005


Overview
A (brief) introduction to data compression
XML lossless data compression
New XML Compression Programs
AXECHOP
TREECHOP

XML Data Compression

A (brief) introduction to XML
Techniques for achieving XML compression
Traditional approaches Huffman, LZ
Specialized approaches
XML Compression Programs
XMill
XGrind
XPRESS

eXtensible Markup Language

separate syntax from semantics
support semi-structured data
support internationalization and platform independence
is self-describing (through labeling of the tree)

eXtensible Markup Language : 2

XML is a framework for defining markup languages:

no fixed collection of markup tags
each XML language is specialized for its own application domain
a common set of generic tools supports processing documents

XML: textual convention to represent tagged trees


eXtensible Markup Language : 3

Code:

<?xml version=  1.0  encoding=  UTF-8  ?>

<Employees>

  <Employee id=  123456  >

  <Name>Homer Simpson</Name>

  <Department>Sector 7-G</Department>

  </Employee>

  <Employee id=  123457  >

  <Name>Frank Grimes</Name>

  <Department>Sector 7-G</Department>

  </Employee>

  

</Employees>

Element
Attribute
Data Value


eXtensible Markup Language : 4

Correctness of an XML document:
Well-formed: complies with XML syntax
Valid: obeys the structure described in a grammar, such as XML schema document
Two kinds of XML parsers:
SAX
DOM

Why Compress XML?

XML is verbose:

Each non-empty element tag must end with a matching closing tag -- <tag>data</tag>
Ordering of tags is often repeated in a document (e.g. multiple records)
Tag names are often long

XML Compressors

View XML as a tree
Separate the tree structure and what is stored in leaves
Save the tree structure so that it can be restored
The compressed file may or may not remember the tree structure

breadfruit tree





XMill: Liefke and Suciu


Tree structure:
Start tags and attribute names are dictionary-encoded
(as T1, T2, etc.)
End tags replaced with / token
Data values are replaced with their container number

Code:

<Book><Title  lang="English">Views</Title>

  <Author>Miller</Author>

  <Author>Tai</Author>

</Book>

More

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[[email protected]]

XML is a popular meta-language that facilitates the interchange and access of data. However, XML's verbose nature tends to increase the size of a data file by as much as ten-fold.

In this seminars, we give a brief introduction to data compression followed by a review of various compression strategies designed specifically for XML data. We then present two novel XML compression techniques, AXECHOP and TREECHOP.

AXECHOP uses a grammar-based approach that exploits the significant structural redundancies within XML documents, while TREECHOP supports querying of compressed XML data without requiring prior decompression.

We compare these two techniques to other XML compression schemes with respect to compression ratio and compression time, and describe our future research.

[shruk56]

XML is a popular meta-language that facilitates the interchange and access of data. However, XML's verbose nature tends to increase the size of a data file by as much as ten-fold. In this seminars, we give a brief introduction to data compression followed by a review of various compression strategies designed specifically for XML data. We then present two novel XML compression techniques, AXECHOP and TREECHOP. AXECHOP uses a grammar-based approach that exploits the significant structural redundancies within XML documents, while TREECHOP supports querying of compressed XML data without requiring prior decompression. We compare these two techniques to other XML compression schemes with respect to compression ratio and compression time, and describe our future research.

[mcr]

hello sir,
i am kukab..my seminar topic is xml data compression..i am in need of document and ppt for my seminar please send me the doc and ppt for xml data compression.
thank you[/size][/font]

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hello sir,
i am kukab..my seminar topic is xml data compression..i am in need of document and ppt for my seminar please send me the doc and ppt for xml data compression.my email id is [email protected]
thank you

[Reshma B.M]

To get full information or details of XML Data Compression please have a look on the pages

http://seminarsprojects.net/Thread-xml-d...5?pid=4211

http://seminarsprojects.net/Thread-xml-data-compression

if you again feel trouble on XML Data Compression please reply in that page and ask specific fields in XML Data Compression

[prakashkrishnanhere]

Hello,
I am doing project on this subject. So, I need some of the information from this book.. Please help me to download this free e-book.. thanking you in advance..