PB情况下散布式应用法度模范的开辟(国外英文资料).docVIP

PB环境下分布式应用程序的开发 Abstract 】 the traditional database applications often adopts client/server structure (C/S) structure, this structure has been very mature in technology and application is very wide also, but the application of this structure system has its shortcomings, such as the query results cannot be Shared, even two customer requests from the same two queries to be executed on the server; A business value query algorithm is stored on the client side; The database server is overloaded and leads to inefficient performance. If between server and client to add a server, specially used to store and temporary query results query algorithm, the problem is to get a good solution: on the one hand, different customers can share a temporary query result without access to the database server again, reduce the burden of the server; There is also no query algorithm for commercial confidentiality on the client side. This is how distributed systems work, and this article describes how to use PowerBuilder to develop distributed applications. Overview of distributed applications The emergence of a distributed system is the result of traditional C/S structure of a number of disadvantages, such as low efficiency, poor security, combining to the database, the global DNS (domain name resolution system) system is a typical example, imagine that a domain name on all the world to manage in a server, the server will certainly because of the heavy load and cannot work normally, the Internet is paralyzed. When writing C/S structure of the database application system, will also meet this kind of problem, that is if the customer number, amount of data and a lot of cases, the server load is very heavy, and a lot of repetitive work, because of the many queries from the customer may be exactly the same query server takes one by one; The query algorithm is also stored on the client side, which may not be suitable for some business environments, because the algorithm itself may need to be kept