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Chapter 20. Database Connectivity. Client Server. Enables a user on a PC to run standard business applications and access corporate shared resources over a network connection. Types of Servers. Print servers File servers Application servers. 3 software layers. Presentation logic
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Chapter 20 Database Connectivity
Client Server • Enables a user on a PC to run standard business applications and access corporate shared resources over a network connection
Types of Servers • Print servers • File servers • Application servers
3 software layers • Presentation logic • Business logic (application) • Database management systems
Centralized vs Distributed • Centralized utilizes a host computer that is accessed using dumb terminals • Distributed processing involves the utilization of multiple computers to fulfill a service request
Two Architectures for Client Server • Two-tiered architecture • Fat client • Database server • Three-tiered architecture • Thin client • Application server • Database server
Fat client • Has presentation software • Has application software • Has API software • Some DBMS software
Thin client • Has presentation software • Some DBMS software
Gateways • Allows clients (or other requestors) to access data stored on various formats • This is a translation type of software that can take a request in one language (SQL) and translate it to something else (DL1, flat files, etc.)
Internet Issues • Availability • Maintenance • Automate functions • Use utilities • Exploit hardware technologies
New Technologies • XML • Java – 3 types of programs • Applets • Servlets • Applications • Java also has JDBC and SQLJ