For efficiency, a topic only exists within the topic space when it has at least one subscriber.
出于效率考虑，只有在至少拥有一个订户的情况下，主题才会存在于主题空间中。
Unless explicitly designed into the message content schema or topic space, a consumer has no knowledge of where a message originated.
消费者不会知道消息是从何处产生的，除非明确地将该消息设计到消息内容计划或着主题空间中。
This logically constructed topic space allows disparate groups of subscribers to create subscriptions that deliver only messages of interest.
这种逻辑主题空间允许不同的订阅者组可以只订阅他们所感兴趣的消息。
Figure 1 is an example of a logically constructed topic space for flight arrival and departure messages.
图1的示例展示了为飞机抵达和起飞消息所设计的逻辑主题空间。
Whereas a queue is associated with a particular bus member (an application server or cluster that is part of the bus), a topic space is part of the bus as a whole.
队列与特定总线成员(属于总线的应用服务器或群集)相关，而主题空间则属于整个总线的一部分。
Placing this big topic in a small space, it's like playing a football match on a basketball court.
把这么大的主题放在如此小的空间里，就如同在篮球场上踢足球一般。
The JMS binding delivers the request to a default messaging provider topic space.
JMS绑定将该请求传递到缺省消息提供程序主题空间。
After the first subscriber subscribes, when messages are published to the topic, the publication point adds the messages to the topic space until the last subscriber unsubscribes.
第一个订户订阅后，发布点会在消息发布到主题时将其添加到主题空间，直到最后一个订户取消订阅为止。
Although you can save bandwidth by using short topics, a well-designed topic space that is more descriptive and that allows the use of wildcards in subscribing applications has substantial benefits.
使用简短的主题虽然可以节约带宽，但一个设计良好的主题空间则应该更具描述性且允许在订阅应用程序中使用通配符，因此更有实际意义和益处。
To create the topic space, complete the following steps.
要创建主题空间，请完成下列步骤。
Last week when we talked about undoing the mess and putting things away, one topic we discussed in the comments was how hard it is to put things away when your home has little to no storage space.
上周我们谈论如何收拾杂物并将他们收起来，谈话中我们讨论的一个话题是在一个小到没有储存空间的家庭要收拾起来有多么困难。
When you create your MQTT application, you must carefully plan the topic space to be logical and to enable flexible subscriptions.
在创建MQTT应用程序时，必须认真将主题空间设计得符合逻辑，并且支持灵活订阅。
Rather than the topic space being defined in a bus member or messaging engine, each messaging engine in the bus has a publication point for the topic space.
主题空间不是在总线成员或消息传递引擎中定义，总线中的每个消息引擎都有一个主题空间的发布点。
Here you focus on configuring a topic space, a topic, and a topic connection factory.
这里我们的重点是配置主题空间、主题和主题连接工厂。
MQTT enforces few rules about the topic space, and you are responsible for designing a logical information space that makes sense for your application.
MQTT对于主题空间有一些强制规定，但设计适合您自己应用程序的逻辑信息空间则由您负责。
Database optimization can become a pretty advanced topic quickly, and I don't have nearly the space here to do this topic full justice.
数据库优化很快会成为一个前沿话题，我几乎没有空间在这里完全公正地做这个话题。
When an application publishes a message to a topic within that topic space, the message flows to every publication point for that topic space, as shown in Figure 5.
当应用程序将消息发布到主题空间中的主题上时，消息将通过该主题空间的所有发布点，如图5所示。
JMS topics are defined with a name, a JNDI name, and a topic name, where the topic name is for the structure defined in the topic space.
使用一个名称、一个JNDI名称和一个主题名称对JMS主题进行定义，其中，结构的主题名称在主题空间中定义。
In the example illustrated above, a partial topic space for MIDI commands is shown.
上面演示的实例显示了MIDI命令的一部分主题空间。
Unfortunately, given space limitation, I'll only cover the most important elements relevant to this article? S topic.
遗憾的是，由于空间所限，我将仅介绍与本文主题相关的最重要元素。
A poorly planned topic space often results in client over-subscription, in which the client subscribes to a broader topic space than required, and thus receives extraneous messages.
而设计糟糕的主题空间则会导致客户的过度订阅，即客户订阅了超出自身所需的主题空间，继而会收到很多无关的消息。
For topics, you also need to provide the topic name and topic space, as shown in Figure 12.
对于主题，您还需要提供主题名称和主题空间，如图12所示。
Experience has shown that a more verbose topic space is preferable to a terse, less descriptive space.
经验表明，详细描述的主题空间要比简单扼要的空间更可取。
The logical topic space allows for a single subscription to request delivery of all information about arrivals and departures into and out of LHR.
此逻辑主题空间应该允许对LHR机场的航班抵达和起飞信息进行单个订阅。
A JMS topic is configured to point to a topic in the topic space; its implementation USES the publication point to send and receive messages on that topic.
JMS主题配置为指向主题空间中的主题；其实现使用发布点发送和接收有关该主题的消息。
To enable SCA modules to use the topic space you created via a JMS binding, you need to create the required JMS artifacts: a JMS connection factory, a JMS topic, and a JMS activation specification.
要使SCA模块能够使用您通过JMS绑定创建的主题空间，您需要创建所需的JMS构件：JMS连接工厂、JMS主题和JMS激活规范。
After you've created a topic space, a topic, and a topic connection factory, you can define a new import JMS messaging binding and, thus, provide this information as described in Figure 16.
创建了主题空间、主题和主题连接工厂后，可以定义新导入JMS消息传递绑定，并按照图16中所示提供此信息。
Notice that the JMS definition for a topic also specifies the topic space.
请注意，主题的JMS定义也将指定主题空间。
An administrator then defines a JMS topic in the provider and associates it with a topic space, which stores and transmits the messages for the topic.
管理员然后可以在提供程序中定义JMS主题，并将其与一个主题空间关联。
Creating a topic space is similar to creating a queue.
创建主题空间与队列相似。
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