不应该应用数据联合模式的领域。
应用数据联合模式时的约束。
这一联合模式从各方面来看都很成功。
数据联合模式可对多个不同信息来源的数据进行虚拟化。
The data federation pattern virtualizes data from multiple disparate information sources.
该功能有助于生成远程模式和联合模式之间的映射。
This feature helps in generation of mappings between remote schema and federated schema.
JEST 联合模式的下一个方面是资源表现方式。
The next aspect of JEST's unification scheme is the resource representation.
社交网络的最后一个特点就是它本身包含一种隐含的联合模式。
A final characteristic of the real-time Web is that it carries with it an implicit model of federation .
有关Feed和小部件的实现选项，请参见企业联合模式部分。
For implementation options for feeds and widgets, see the syndication pattern section.
这是由于数据联合模式中的请求对应的响应的实时同步特征造成的。
This is due to the real-time, synchronous nature of responding to requests in the data federation pattern.
数据联合模式的实现在其可以集成的具体源模型的能力方面各有不同。
Implementations of the data federation pattern vary in their capabilities which specific source models they can integrate.
数据联合模式允许以实时集成的方式访问源，具有最高的数据并发级别。
The data federation pattern allows for real-time, integrated access to sources with the highest level of data currency.
联合模式的重点是让数据保持在原来的位置，并提供实时的虚拟集成视图。
The focus of the federation pattern is to leave data in place and to provide a real-time, virtual, integrated view.
数据联合模式要求对集成视图范围内来自各个数据源的数据元素进行映射。
The data federation pattern requires the mapping of data elements from various data sources that are within the scope of the integrated view.
数据联合模式的重点是数据源的集成和通过面向数据的接口提供单个系统映像。
The data federation pattern focuses on the integration of data sources and provides a single system image through a data-oriented interface.
在大多数情况下，由于写访问非常复杂，因此数据联合模式主要用于进行读访问。
In most cases, the data federation pattern is used for read access because of the complexity of write access.
数据联合模式的实现通常至少支持其中一种模型，有时候会同时支持这两类模型。
Implementations of the data federation pattern typically support at least one of those models, sometimes both.
研究表明，当必须集成多个源时，使用数据联合模式可帮助大幅度减少开发时间。
Studies have shown that using the data federation pattern helps to reduce development time significantly when multiple sources have to be integrated.
为了应对这些挑战，架构师将需要把数据联合模式与其他安全相关的模式结合使用。
In order to address those challenges, architects will need to combine the data federation pattern with other security-related patterns.
数据联合模式的一个非常重要的好处是，能够屏蔽在源系统中实现的很多模型更改。
A very significant benefit to the data federation pattern is the ability to mask off many model changes which may be implemented in the source systems.
应用数据联合模式时，务必理解其特征以及其受以下所述的非功能要求的影响情况。
When applying the data federation pattern, it is important to understand its characteristics and how it is affected by the non-functional requirements described below.
如果不使用联合模式，应用程序必须通过不同的接口和不同的协议与多个源分别交互。
Without using the federation pattern, the application must interact with multiple sources individually through different interfaces and different protocols.
在传统上下文中应用数据联合模式的解决方案可以利用SQL的声明性和灵活性特征。
Solutions that apply the data federation pattern in the traditional context leverage the advantage of the declarative and flexible nature of SQL.
数据联合模式的有些实现可以将部分或全部子操作(子查询)以并行方式发送到集成源系统。
Some implementations of the data federation pattern are capable of sending some or all of the sub-operations (sub-queries) in parallel to the integrated source systems.
因此，大部分数据联合模式的实现对复杂转换功能的关注相对较少，而更强调查询优化技术。
Therefore, most implementations of the data federation pattern focus less on complex transformation capabilities and more on query optimization technologies.
我们最后将总结何时应用数据联合模式及何时不应用此模式，并将列出重要的约束。
We will conclude by summarizing when to apply and when not to apply the data federation pattern and to list important constraints.
数据联合模式的大部分实现都比较强调一个（或数量很有限的）目标模型，以最有效地处理请求。
Most implementations of the data federation pattern have a relatively strong focus on one -- or a very limited number of -- target models in order to process requests most efficiently.
不过，复杂转换对联合模式的性能有负面影响，从而会降低此模式对此类场景的适用性。
However, complex transformations have a negative impact on the performance of the federation pattern and make this pattern less applicable for those scenarios.
举一个协调合作的例子，Kelty介绍了Apache和Linux系统在联合模式下的讨论。
For examples of coordinated collaboration, Kelty points to the debate between organizational models for Apache and Linux.
由于数据联合模式并不会创建源数据的副本，因此源更改并不一定要采用这种方法进行传播或处理。
Since the data federation pattern does not create copies of source data, source changes do not have to be propagated or processed in this approach.
基于以上分析提出虚拟现实技术和城市供水管网模型联合模式总体框架及其技术优势。
The overall framework of combining with the virtual reality technology and urban water network model was put forward and its technological superiority was expounded on the basis of the above analysis.
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