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Emerging Database Technologies and Applications. Talal A. Alsubaie. Outline. Mobile Database. Multimedia Database. GIS ( Geographic Information Systems ). Mobile Database. Mobile Database. Portable devices and wireless technology led to mobile computing.
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Emerging Database Technologies and Applications Talal A. Alsubaie
Outline • Mobile Database. • Multimedia Database. • GIS ( Geographic Information Systems ). Talal A. Alsubaie
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. • Wireless coverage. • Battery. • Changes in network topology. • Wireless Transmission Speed. Talal A. Alsubaie
Mobile Database • Mobile Computing Architecture: Talal A. Alsubaie
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. Talal A. Alsubaie
Characteristics of Mobile Environments • Communication latency • Intermittent connectivity • Limited battery life • Changing client location • All of these Characteristics impact data management in mobile computing. Talal A. Alsubaie
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. Talal A. Alsubaie
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. Talal A. Alsubaie
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. Talal A. Alsubaie
Data Management Issues • Mobile databases can be distributed under two possible scenarios: • The entire database is distributed mainly among the wired components, possibly with full or partial replication. • 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. Talal A. Alsubaie
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 Talal A. Alsubaie
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. Talal A. Alsubaie
Application: Intermittently Synchronized Databases Insert\Update Data Talal A. Alsubaie
Multimedia Databases • In the years ahead multimedia information systems are expected to dominate our daily lives. Talal A. Alsubaie
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. • Text. • Graphics. • Images. • Animation. • Video. • Audio. • … Talal A. Alsubaie
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. Talal A. Alsubaie
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. Talal A. Alsubaie
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). Talal A. Alsubaie
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. Talal A. Alsubaie
Multimedia Database Applications • Documents and records management • Knowledge dissemination • Education and training • Marketing, advertising, retailing, entertainment, and travel • Real-time control and monitoring Talal A. Alsubaie
Geographic Information Systems • Geographic information systems(GIS): • A systematic integration of hardware and software for capturing, storing, displaying, updating manipulating and analyzing spatial data. Talal A. Alsubaie
title Geographic 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 Talal A. Alsubaie
Geographic Information Systems Talal A. Alsubaie
Characteristics of Data in GIS • There are several aspects of the geographical objects need to be considered: • Location. • Temporality. • Complex Spatial Features. • Object ID. • Data Quality. • … Talal A. Alsubaie
Characteristics of Data in GIS • The geographic context, topologic relations and other spatial relationships are fundamentally important in order to define spatial integrity rules. Talal A. Alsubaie
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. Talal A. Alsubaie
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. Talal A. Alsubaie
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. Talal A. Alsubaie
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 geo-objects. Talal A. Alsubaie
GIS Standers and Operations • Spatial Relationship Standard: • Equal. • Intersect. • Touch. • Cross. • Within. • … and more. Talal A. Alsubaie
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. Talal A. Alsubaie
GIS Standers and Operations CREATETABLE STATES ( SnameVARCHAR(50) NOTNULL, State_shapePOLYGONNOTNULL, Country VARCHAR(50) NOTNULL, PRIMARYKEY (Sname), FOREIGNKEY (Country) REFERENCES COUNTRIES (Cname) ); SELECTSname FROM STATS WHERE (AREA (State_shape) > 50000) Talal A. Alsubaie
Future of GIS • There are some challenges in developing GIS applications: • Data Source. • Data Model. • Standards. • Mobile GIS. • Specialized DBMS for GIS. • … Talal A. Alsubaie