Internet is the de facto standard of today's global communications

Database systems with an architecture suited for Internet data communications

These systems combine spatial database and internet technologies to provide a distributed and network-centric approach to spatial information

Distinct architectures - integrate spatial database software tools, server-to-database middleware, application programming languages, and Internet markup languages

Used with new data collection, processing and dissemination technologies - for example, web cameras, weather stations, in-vehicle navigation systems etc.

Serve varied business functions - for example, e-commerce, location-based services and self-served information kiosks

Widest possible audience - with users whose knowledge, skill and ability of using a database is different

Opportunities

• Interoperability in a distributed computing environment
• Hardware and software independence
• Rapid deployment and universal accessibility at a management cost
• Lowering the cost of using spatial information technology
• Improved spatial information customer services

Challenges

• Inherent limitations of the web (html/xml) services, not geodatabase
• Inherent limitations of spatial databases, too large a packet
• Security and privacy concerns
• Copyright control of abuse and misuse

Generic Architecture

1st Tier - from a users perspective: presentation tier, e.g., browser or other client

2nd Tier - communication infrastructure tier i.e. network connections

3rd Tier - business logic tier - rules and capabilities; web server - Internet connection between client and server & web activity engine - Internet mapping or processing

4th Tier - from systems capability perspective - data management tier i.e., spatial database management, data warehouse, other database connections

Interactive web architecture

Object web architecture

Web services model

The interactive web architecture using CGI (Common Gateway Interface) and server API

The object web architecture based on the CORBA/Java standard

Spatial database applications using the Web Services Model

1. Purpose of implementing the spatial database system
2. Audience or users of the system
3. Technology supporting the system
4. Architecture of the system
5. Spatial data to be served by the system
6. Application requirements and constraints
7. Cost of capital investment in the system
8. Legislation and regulations for collection, access to and application of spatial data

Information-centric vs application-centric approach

Organisational vs infrastructural approach

In-house Development vs outsourcing

Client-oriented vs server-centred approach

Queries about this Lesson, please send them to: jmwaura@jkuat.ac.ke

*References*

• Database Systems: Design, Implementation, and Project Management, Springer. Albert K W Yeung & G. Brent Hall
• Database Systems: Design, Implementation, and Management, 12th ed. Carlos Coronel & Steven Morris
• Database Modeling and Design; Logical Design, 5th ed. Taby Teorey et.al
• Fundamentals of database systems, 6th ed. Ramez Elmasri & Shamkant B. Navathe