a multi-model xml (mmx) framework for digital video library (dvl) systems
DESCRIPTION
A Multi-Model XML (MMX) Framework for Digital Video Library (DVL) Systems. Presented by: Jacky Ma Date: 11 Dec 2001. Presentation Outline. Introduction Background An Example The Problem The MMX Framework Models Syntax Behaviors Conclusion Contribution Difficulties. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
A Multi-Model XML (MMX) Frameworkfor
Digital Video Library (DVL) Systems
Presented by: Jacky Ma
Date: 11 Dec 2001
Presentation Outline Introduction
Background An Example The Problem
The MMX Framework Models Syntax Behaviors
Conclusion Contribution Difficulties
IntroductionIntroduction
Background
Previous Research Digital Video Library (DVL) Extensible Markup Language (XML)
Motivation Facilitate searching in DVL with XML Search XML in specialized and customizable
way
An XML Example<key N="7" S="3" E="16" W="1"/><node id="1">
<key N="7" S="3" E="6" W="1"/><node id="1">
<key N="7" S="5" E="2" W="1"/><data x="1" y="5">itemA</data><data x="2" y="7">itemB</data>
</node><node id="2">
<key N="4" S="3" E="6" W="4"/><data x="4" y="3">itemA</data><data x="6" y="4">itemC</data>
</node></node><node id="2">
<key N="6" S="4" E="16" W="8"/><node id="1">
<key N="5" S="4" E="8" W="9"/><data x="8" y="4">itemG</data><data x="9" y="5">itemD</data>
</node><node id="2">
<key N="6" S="5" E="11" W="16"/><data x="11" y="5">itemF</data><data x="16" y="6">itemE</data>
</node></node>
Document
Element "Key"
Element "Node"
Element "Data"
Queried by XPath
Based on the XML structure and the data Retrieve the node “data” containing attribute
“x=8” //data[@x=‘8’]
Can also retrieve the parent-node, sibling-node, etc. /node[1]/node[1]/key/following-sibling::*
Useful in XSLT
Queried by RDBMS
id1
N1
S1
E1
W1
id0
N0
S0
E0
W0
x y data
1 7 3 6 1 1 7 5 2 1 1 5itemA
1 7 3 6 1 1 7 5 2 1 2 7itemB
1 7 3 6 1 2 4 3 6 4 4 3itemA
1 7 3 6 1 2 4 3 6 4 6 4itemC
2 6 416
8 1 5 4 8 9 9 5itemD
2 6 416
8 1 5 4 8 9 8 4itemG
2 6 416
8 2 6 511
16
11
5itemE
2 6 416
8 2 6 511
16
16
6itemE
Based on the data Classical “select * from” clause Can retrieve any item based on its
attributes
Queried by R-Tree
How about if I told you it is a R-Tree? Spatial Queries
Give me the point at (2,7) Give me the point nearest to (4,4)
Nearest Neighbor Search Give me the point nearest to “itemB”
(0,0)
What makes the difference?
Make use of knowledge we have on the data given.
We can do the spatial query ONLY if we know the data segment is representing a R-Tree, and understand what are the attributes (id, N, S, E, W, etc.) representing.
Problem
There are a lot of different data structures, different data manipulations, and different query methods.
How could we model them with XML?
The MMX FrameworkThe MMX Framework
The MMX Framework To solve the previous problem:
A framework allowing various data structures to be implemented upon
Knowledge on knowledge Describe the structural information of XML Document Empirical knowledge Analogeous to RDF
Manipulation of information with structural information Queries Updates Exchanging information
Model the “Models”
The kinds of “Models” is unlimited They may looks “similar”, all of them can
be represented by graphs or XML tree But the underlying structures, constraints
and algorithms are different No generic descriptive syntax Use a “label” and “procedural” approach
Label “known” structures, and Program the “new” structures
Major “Labeled Models”
Generic Object Vector Relational Document Tree
Basic Model
Abstract Data Object (ADO) Encapsulate the information about a package
of structured data Accessible at Root Pointing out at Child Node Includes:
Model Name Properties Behaviors Data
Abstract Data Object:Properties,Behaviours,
Data
Head Node
Leave Nodes
In References
Out References
Parent Node
Child Node
Child Node
Child Node
Out References
Syntax Serialization Syntax
Embedded in XML Document Defines elements like <ado>, <property>, etc. Easy to use Change the document instance
Schema Syntax Embedded in XML Document Schema Associate element names with structural information More complicated Do not need to change the document Favors reusability, scalability and interoperability
Behaviors
Behaviors The program to manipulate the data “Default” Behaviors allow operations on any
standard ADOs
Properties Persistent variables Keeping the state of the ADO
Data User data Appear as DOM Tree to the Behavior program
ConclusionConclusion
Contribution
Propose a representation to encapsulate data structures
A procedural model to manipulate the data Promote the use of interoperable data structure
format Describe how will typical “Models” functions Describe the “Tree” model which features spatial
queries, and particularly suitable for searching in DVL
Difficulties
No general syntax can precisely describe all kinds of data structures
Not possible to include all data structures one-by-one
Research Direction
Develop the full specification for the MMX Framework
Develop various structures that tailored for content-based searching in DVL
Q&AQ&A