澳洲酒店管理学论文代写:数据库

澳洲酒店管理学论文代写:数据库

数据库设计过程的一个重要组成部分的步骤II(b),集成不同的用户浏览到一个统一的,没有多余的全球模式。个人的观点最终用户代表一个概念性的数据模型和概念模型的综合分析结果不是最终用户解决任何分歧意见和术语。经验表明,几乎所有的情况都可以以一种有意义的方式解决,通过集成技术。发生在一个不同的用户或用户组的多样性模型开发自己的世界的独特的视角,或者至少是由企业在数据库中。例如,营销部门往往整个产品销售的基本单位,工程部可以专注于整个产品的各个部分。在另一起案件中,一个用户可以查看一个项目,其目标和规定,以实现这些目标的进展,但其他用户可以查看一个项目,它的资源需求和涉及的人员。造成这种差异在概念模型中,似乎有不兼容的关系和术语。这些差异出现在概念数据模型中,不同层次的抽象,之间的联系(一个对许多人来说,许多许多,等等),或者相同的概念是作为一个实体建模,基于用户属性或关系的观点。如果数据库移植到另一个数据库管理系统支持类似的结构(例如,另一个关系数据库管理系统或一个新版本的相同的数据库管理系统有不同的性能属性),逻辑数据模型可以作为新的物理数据模型的基础。

澳洲酒店管理学论文代写:数据库
An important component of the database design process steps II ( b ), Integration of different users to browse to a unified, no redundant global schema. The views of individual end users represented a conceptual data model and concept model of comprehensive analysis results is not the end user to resolve any divergence of views and terminology. Experience has shown that almost every situation can be resolved in a meaningful way, through the integration technology. Occurs when a different model of the diversity of users or user groups to develop their own unique perspective of the world, or at least is represented by enterprises in the database. For example, the marketing departments often have the entire product as the basic unit of sales, Engineering Department can concentrate on the individual parts of the entire product. In another case, a user can view a project, its objectives and provisions in order to achieve these goals progress over time, but other users can view an item, its resource needs and the personnel involved. Cause such differences in conceptual models, there seems to be not compatible with the relations and terminology. These differences appear in the conceptual data model, as different levels of abstraction, the connection between (one to many, many to many, and so on), or to the same concept was modeling as a entity, attribute or relation based on the user’s point of view.If the database is transplanted to another DBMS support similar structure (for example, another relational database management system or a new version of the same database management systems have different Performance attributes), logical data model can be used as the base of new physical data model.

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