外文翻譯-sqlserver體系結(jié)構(gòu)-文庫(kù)吧在線文庫(kù)
【正文】 easier to use than database APIs but may not expose as much functionality as an API.ActiveX Data Objects Microsoft ActiveX Data Object(ADO) encapsulate the OLE DB API in a simplified object model that reduces application development and maintenance costs. ADO can be used from Microsoft Visual Basic, Visual basic for applications, Active Server Pages(ASP), and the Microsoft Internet Explorer scripting object model.Remote Data Object Remote Data Object(ROD) map over and encapsulate the ODBC API. RDO can be used from Visual Basic and Visual Basic for applications. WITH SQL SERVER Designing An Application For SQL ServerPlanning a database design requires knowledge of the business functions that you want to model and database concepts and features that you use to represent those business functions.Before you design an application for SQL Server, it is important to spend time designing a database to model the business accurately. A welldesigned database requires fewer changes and generally performance more efficiently. The architecture that you select affect how you develop, deploy and manage your software application. Software ArchitectureYou can use one of several application architecture to implement client/server applications. However, selecting a layered application approach affords flexibility and a choice of management options. You can divide software applications into three logical layers, which can physically reside on one or more servers. DesignTypical application deployment options include:Intelligent Server(2tier) Most processing occurs on the server, with presentation services handled on the client. In many instance, most of the business services logic is implemented in the database. This design is useful when clients do not have sufficient resources to process the business logic. However, the server can bee a bottleneck because database and business services pete for the same hardware resources.Corporate applications designed from a databasecentric point of view are an example of this design.Intelligent Client(2tier) Most processing occurs on the client, with presentation services handled on the server. This design is widely used. However, network traffic can be heavy and transactions longer, which can in turn affect performance.Applications developed for small organizations with product such as Microsoft Access are an example for this design.NTier Processing is divided among a database server, an application server, and clients,. This approach separates logic from data services, and you easily can add more application servers or database servers as needed. However, the potential for plexity increases, and this approach may be slower for small applications.Multitiered enterprise application and applications developed with transaction processing monitors are examples for this design.Internet Processing is divided into three layers, with the business and presentation services residing on the Web server and the clients using simple browsers. Any client that has a browser can be supported, and software does not need to be maintained on the client.An example of this design is a Web site thar uses several Web servers to manage connections to clients and a single SQL Server database that services requests for data. A SQL SERVER DATABASEImplementing a SQL Server database
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