Emerging Database Technologies
and Applications
Talal A. Alsubaie
Outline
• Mobile Database.
• Multimedia Database.
• GIS ( Geographic Information Systems ).
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Mobile Database
Mobile Database
• Portable devices and wireless technology led to mobile computing.
• Portable computing devices and wireless communication allowed the
client to access data from any ware and any time.
• There are some HW and SW problems that must be solved to make
maximum exploitation of mobile computing.
– i.e. Database recovery.
• Hardware problems are more difficult.
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Wireless coverage.
Battery.
Changes in network topology.
Wireless Transmission Speed.
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Mobile Database
• Mobile Computing Architecture:
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Mobile Database
• Mobile Ad-Hoc Network (MANET):
– In a MANET, co-located mobile units do not need to communicate
via a fixed network, but instead, form their own using cost-effective
technologies such as Bluetooth.
– In a MANET, mobile units are responsible for routing their own
data, effectively acting as base stations as well as clients.
– MANET must be robust enough to handle changes in network
topology.
• Such as arrival or departure of mobile unites.
– MANET can fall under P2P architecture.
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Characteristics of Mobile Environments
– Communication latency
– Intermittent connectivity
– Limited battery life
– Changing client location
– All of these Characteristics impact data
management in mobile computing.
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Characteristics of Mobile Environments (2)
– The server may not be able to reach the client
or vise versa.
– We can add proxies to the client and the server
to cache updates into when connection is not
available.
– After the connection is available proxy
automatically forward these updates to its
distention.
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Characteristics of Mobile Environments (3)
– The latency involved in wireless communication makes
scalability a problem.
• Since latency increases the time to service each client request,
so the server can handle fewer clients.
– Servers can use Broadcasting to solve this problem.
– Broadcast well reduces the load on the server, as clients
do not have to maintain active connections to it.
• For example weather broadcasting.
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Characteristics of Mobile Environments (4)
• Client mobility also poses many data management
challenges:
– Servers must keep track of client locations in order to efficiently
route messages to them.
– Client data should be stored in the network location that minimizes
the traffic necessary to access it.
– The act of moving between cells must be transparent to the client.
• Client mobility also allows new applications that are
location-based.
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Data Management Issues
• Mobile databases can be distributed under two possible
scenarios:
1.
The entire database is distributed mainly among the wired
components, possibly with full or partial replication.
•
2.
Management is done in fixed hosts, with additional functionalities.
The database is distributed among wired and wireless
components.
•
Management is done in both fixed hosts and mobile units.
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Data Management Issues
– Data distribution and replication (Cache)
– Transactions models
– Query processing (where data is located?)
– Recovery and fault tolerance
– Mobile database design
– Location-based service
– Division of labor
– Security
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Application: Intermittently Synchronized Databases
• The client has his own application and DBMS in his local laptop.
• Do some updates locally and connect to the server via internet to get
batch of updates (synchronization).
• The primary characteristic of this scenario is that the clients are mostly
disconnected; the server is not necessarily able reach them.
• This environment has problems similar to those in distributed and
client-server databases, and some from mobile databases.
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Application: Intermittently Synchronized Databases
Insert\Update Data
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Multimedia Database
Multimedia Databases
• In the years ahead multimedia information systems are expected to
dominate our daily lives.
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Nature of Multimedia Data and Applications
• DBMSs have been constantly adding to the types of data
they support.
• Today many types of multimedia data are available in
current systems.
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Text.
Graphics.
Images.
Animation.
Video.
Audio.
…
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Nature of Multimedia Applications
• Multimedia data may be stored, delivered, and utilized in
many different ways.
• Applications may be categorized based on their data
management characteristics.
– Repository applications.
• A large amount of multimedia data as well as metadata is stored for retrieval
purposes.
– Presentation applications.
• Simple multimedia viewing of video or audio data.
– Collaborative work using multimedia information.
• Which engineers may execute a complex design task by merging drawings,
fitting subjects to design constraints, and generating new documentation,
change notifications, and so forth.
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Data Management Issues
• Multimedia applications dealing with thousands of
images, documents, audio and video segments,
and free text data depend critically on:
– Appropriate modeling of the structure and content of
data.
– Designing appropriate database schemas for storing and
retrieving multimedia information.
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Data Management Issues (cont.)
• Multimedia information systems are very complex and
embrace a large set of issues:
– Modeling:
• Complex Objects, dealing with large number of types of data (Graphics).
– Design:
• Conceptual, logical, and physical design of multimedia has not been addressed
fully, and it remains an area of active research.
– Storage:
• Multimedia data on standard disk devices presents problems of representation,
compression, mapping to device hierarchies, archiving, and buffering during the
input/output operation.
• DBMS has presented the BLOB type (Binary Large Object).
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Data Management Issues (cont.)
• Multimedia information systems are very complex and
embrace a large set of issues (cont.):
– Queries and retrieval:
• The database way of retrieving information is based on query languages and
internal index structures.
– Performance :
– Multimedia applications involving only documents and text, performance
constraints are subjectively determined by the user.
– Applications involving video playback or audio-video synchronization, physical
limitations dominate.
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Multimedia Database Applications
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Documents and records management
Knowledge dissemination
Education and training
Marketing, advertising, retailing, entertainment,
and travel
• Real-time control and monitoring
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Geographic Information
Systems (GIS)
Geographic Information Systems
• Geographic information systems(GIS):
– A systematic integration of hardware and software for
capturing, storing, displaying, updating manipulating
and analyzing spatial data.
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Geographic
title
Information Systems
• GIS can be divided into two formats:
– Vector data represents geometric objects such as points, lines, and
polygons.
– Raster data is characterized as an array of points, where each point
represents the value of an attribute for a real-world location.
• Informally, raster images are n-dimensional array where each entry is a
unit of the image and represents an attribute
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Geographic Information Systems
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Characteristics of Data in GIS
• There are several aspects of the geographical
objects need to be considered:
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Location.
Temporality.
Complex Spatial Features.
Object ID.
Data Quality.
…
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Characteristics of Data in GIS
• The geographic context, topologic relations
and other spatial relationships are
fundamentally important in order to define
spatial integrity rules.
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Constraints in GIS
• Topology Integrity.
– Deals with the behavior of features and the spatial
relationship between them.
• Semantic Integrity.
– Deals with the meaning.
• User Defined Integrity.
– Business rules.
• Temporal.
– Punctual and Durable.
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Conceptual Data Models for GIS
• Briefly describes the common conceptual models
for storing spatial data in GIS.
• Some conceptual data models:
– Raster data model:
• Used for analytical applications.
– Vector data model:
• Analysis is done using a well defined set of tools.
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Conceptual Data Models for GIS
• Some conceptual data models (cont.):
– Network model:
• Define how lines connect to each other in a point.
• Rules are stored in a connectivity table.
• Example of everyday application, optimizing a school bus route.
– TIN data model:
• Triangular Irregular Network.
• Is a vector-based approach.
• models surfaces by connecting sample points as vector
of triangles.
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DBMS Enhancements for GIS
• Until the mid 1990s, GIS system was based mainly on file-based
systems.
• No transfer standards was defined, which limited vendors in terms of
sharing.
• Involved in a geo-structure and attributes was stored in DBMS.
• The spatial features was kept in a file and linked to the attributes.
• Could not take FULL advantage of commercial RDBMS.
• Database extensions has been released by vendors like DB2 spatial
extender, and OracleSpatial and OracleLocator to support GIS data.
• These extensions allowed the user to store, manage, and retrieve geoobjects.
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GIS Standers and Operations
• Spatial Relationship Standard:
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Equal.
Intersect.
Touch.
Cross.
Within.
… and more.
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GIS Standers and Operations
• Spatial Analysis Standard:
– Distance.
• Returns the shortest distance between any two points in two
geometries.
– Buffer.
• Returns a geometry that represents all points whose distance
from the given geometry is less than or equal to distance.
– Convex Hull.
– Union.
– And more.
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GIS Standers and Operations
CREATE TABLE STATES (
Sname
VARCHAR(50)
NOT NULL,
State_shape
POLYGON
NOT NULL,
Country
VARCHAR(50)
NOT NULL,
PRIMARY KEY (Sname),
FOREIGN KEY (Country) REFERENCES COUNTRIES (Cname)
);
SELECT Sname
FROM STATS
WHERE (AREA (State_shape) > 50000)
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Future of GIS
• There are some challenges in developing GIS
applications:
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Data Source.
Data Model.
Standards.
Mobile GIS.
Specialized DBMS for GIS.
…
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Questions ?
Thanks