Patterns for Three-Tier Client/Server Applications

Abstract

Database Interface, makes the application portable to different database platforms. Pattern 4, ORB Proxy for Database Object, deals with the integration of the often incompatible worlds of object brokers and object databases. Pattern 5, Automatic Object Locks, liberates developers from the tedious and error-prone work of manually locking and unlocking database objects. Pattern 6, Shared DB Connections, applies to the cases where it is necessary to have more simultaneous users than the number of connections the database servers will accept. This leads to pattern 7, Thread-Based Figure 1: Three-tier architecture. Application Server Database Server Concurrency Management, which shows how concurrency control can be implemented in application servers when database locks can no longer be used to36217-673 the clients. While pattern 5 is fairly C++-specific, the other patterns should apply to most object-oriented threetier application development projects. Pattern 1: Three-Tier Architecture..