Web-based Schema Integration System

eyelashesnectarineSoftware and s/w Development

Nov 3, 2013 (4 years and 1 month ago)

115 views

Web
-
based Schema Integration
System

A research on Data Integration

Supervisor: Dr Le Minh Duc

Student: Tran Thi Linh

Outline

I.
Schema Integration Overview

II.
Web
-
based Schema Integration System

1.
System Architecture Overview

2.
Key functions in the system.


Display schemas


Integration Performing


Display Integration output

Web
-
based

Schema Integration System

I.
Schema Integration Overview

Schema integration problem is dealing with the
heterogeneity in database management.


In database management, the designers use various
forms to structure and model the database. (flat
files, semi
-
structured models such as ERD, relational,
UML, XML)


On demand of merging different databases, we need
to integrate their schema models into a single
schema first.

Web
-
based

Schema Integration System

I.
Schema Integration Overview


Examples of various forms of heterogeneity:


Entity
-
Relationship with Constructs: Entity


attribute


relationships and constraints (i.e. cardinality)


Web
-
based

Schema Integration System

I.
Schema Integration Overview


The various forms of heterogeneity:


Relational Model with Constructs: Table


Field


Keys



Web
-
based

Schema Integration System

I.
Schema Integration Overview


The various forms of heterogeneity:


UML



Web
-
based

Schema Integration System

I.
Schema Integration Overview


AutoMed Data Integration System:


A desktop
-
based application


It is a framework comprising of a graphical tool (Swing GUI)
and a programmer API for conducting Data Integration
Tasks


Its features


Wrapping schema from relational databases


Representing schema in high level graph based model


Using a common data model named Hyper
-
graph based model
(HDM)


HDM: low level data model comprising of 3 primitive constructs
for representing a model: Nodes


Edges
-

Constraints


Provide a data integration engine which is implemented in Java
that supports query processing over schema




Web
-
based

Schema Integration System

I.
Schema Integration Overview


AutoMed Data Integration System


» Could we use it over the Internet, i.e. running it on
the web?



Web
-
based

Schema Integration System

II.
Web
-
based Schema Integration
System


Overall idea: originate from AutoMed


Create a schema integration that runs on the Web


Using AutoMed API as the schema integration engine.
(i.e. AutoMed serves as a web server)


Web
-
based

Schema Integration System

1.
System Architecture Overview


AutoMed system architecture

Web
-
based

Schema Integration System

II.
Web
-
based Schema Integration System


Our proposed web
-
based schema integration system architecture











Web browsers
: send request for schema integration functions to server

Web Server
: where AutoMed Engine is placed, process requests, then send the
response

» we define a data structure for storing schemas’ information and the Draw
function using this information to represent input and output of schema
integration process

»To manipulate with the schemas and the models that are stored in the
repository, we use AutoMed API. That why we said using AutoMed API as
schema engine for our system


Web
-
based

Schema Integration System

2.
The key functions in the system


Display schemas


Performing integration


Display integration output

Note that: our proposed system focuses on 2 challenges
to deal with Schema Integration problem


The heterogeneity in database


How to perform it on the Web


Web
-
based

Schema Integration System

II.
Web
-
based Schema Integration System

Display Schemas


In AutoMed:


Represent schemas in graphs that nearly have the
same view as the traditional view of specific models


ERD:



Web
-
based Schema Integration System

Display Schemas


In AutoMed:


Represent schemas in graphs that nearly have the
same view as the traditional view of specific models


Relational:



Web
-
based Schema Integration System

Display Schemas


In AutoMed:


Represent schemas in graphs that nearly have the
same view as the traditional view of specific models


UML:



Web
-
based Schema Integration System

Display Schemas


Our solutions:


Using a common layout for all kinds of models: A graph
of circle with points are schema objects such as: entity,
attribute, relationship, relation, fields …


To display schemas on web: using SVG/ JavaScript



Web
-
based Schema Integration System


Web
-
based Schema Integration System


Web
-
based Schema
Integration System

For UML

Integration Performing


There are some schemas(let’s call
source schemas
),
we need integrate them into a single schema (let’s
call
global schema
) which covers all schemas. From
this single schema we can query data from all source
schemas.


To make it simple:



performing integration is the process of mapping a
schema to a global schema. (with n source schemas we
do it n
-
times)



Web
-
based Schema Integration System

Integration Performing


Steps/ activities
:


Compare schemas
:


Determine the correspondences among concepts
between schemas


Detect the conflicts between schemas


Conforming schemas
:


Resolve conflicts, align schemas to make them
compatible


To do it:
apply transformations to schema
: adding more,
deleting, renaming schema objects …


» basically, we call this step as
mapping schemas


Web
-
based Schema Integration System

Integration Performing


In AutoMed:


Using bidirectional pathway as Both
-
as
-
view mapping
technique.


Transform source schemas into a common hyper
-
graph data
model (HDM)


HDM is a low level model. It comprises of 3 primitive constructs for
representing a schema model: Nodes


Edges
-

Constraints


There are mapping rules to define how to map these modeling
constructs into those in other high level data models.


For example, Nodes are mapped to Entity in Entity
-
Relationship
model, Edge is a combination of an entity and a relationship


In the AutoMed, the transformation models into HDM models is
done automatically.


Web
-
based Schema Integration System

Integration Performing


Our solutions
:


Visually compare schemas on the web: display 2
schemas at the same time


Schemas are displayed in a common layout


To create mappings for schema: user interacts with the
schema objects to define transformation steps


Web
-
based Schema Integration System

Web
-
based Schema Integration System


Display Integration Output


Showing mappings or transformation user created


In AutoMed:


Transformation pathway is represented as a directed graph
(called a network)


No comparative view over 2 or more pathways:


Set of pathways between 2 schemas in case of different ways
for defining transformation


Our solutions:


Using the common layout stated before for both schema
and pathway.


Using concentric circles with different radii for a set of
pathways between 2 schemas


Using a system of circles that share the a common point for
2 or more pathways connected to a given schema.



Web
-
based Schema Integration System

Display Integration Output


Showing mappings or
transformation user
created


In AutoMed:



Web
-
based Schema Integration System

Display Integration Output


Showing mappings or transformation user created


Our solutions:



Web
-
based Schema Integration System


Web
-
based Schema
Integration System


Web
-
based Schema
Integration System


Web
-
based Schema
Integration System

Thank you for your attention!