An important part of SDO is to make data manipulation easier. So once a data Graph is constructed, it is important to be able to traverse the tree and to access its elements with the SDO API.
SDO有一个很重要的特点就是使数据操作变得更容易了，因此一旦构造好一个数据图，很重要的一点就是需要使用SDOAPI来遍历树结构，并访问其中的元素。
After you collect those statistics, you get the new access plan graph shown in Figure 10.
您收集了这些统计数据之后，会得到如图10所示的新访问计划图。
So far, you learned how to create metadata, then populate and access a data graph corresponding to the metadata.
到目前为止，您已经了解了如何创建元数据，然后填充和访问与元数据对应的数据图。
You can obtain the statistics from the table descriptor of the table node in the underlying access path graph.
您可以从基础访问路径图中的表节点的表描述符处获得该统计信息。
There is no FETCH or table node shown in the access path graph because it is an index-only scan.
因为其是一个唯一索引扫描，所以在访问路径图中不显示FETCH或表节点。
To see the table descriptor, right-click the table node in the access path graph.
为了查看表描述符，请右键单击访问路径图上的表节点。
The rest of this section takes you through the access path graph one more time from the data flow perspective so that you can gain a full understanding of the performance aspect of query execution.
本节的其余部分再一次以数据流的观点向您介绍访问路径图以便您可以在查询执行的性能方面获得充分的理解。
This article described the basic concepts of access paths and how to read an access path graph.
本文描述了访问路径的基本概念以及如何解读访问路径图。
It includes how to understand the problem query better by using the visual AIDS provided by query formatting, annotation, reports, and the access plan graph.
其中包含如何通过使用查询格式化、注释、报告和访问计划图来更好地理解问题查询。
Data flows from the bottom up (as displayed in the graph) and is processed by operation nodes in the access path graph.
数据从下往上流动(如访问路径图所示)并通过访问路径图上的操作节点处理。
Designing a data graph could be the subject of another article on its own as there are many scenarios to consider when building access to a data source.
因为建立对数据源的访问要考虑很多种情况，设计数据图本身可以作为另一篇文章的主题。
From the access plan graph, you can see what choices the optimizer has made regarding how the query will be processed and the rationale for those choices.
从这张访问计划图中，您可以看到优化器对如何处理查询作出何种选择以及理由。
There is an attribute RUNSTATS TIMESTAMP on the table or index node of the access plan graph that indicates the last time when the statistics were collected.
在访问计划图的表或索引节点上会有一个RUNSTATSTIMESTAMP属性，它表示收集统计数据的时间。
One of the powerful features of SDO is the flexibility applications have in how they access data within a graph.
SDO的强大功能之一是应用程序可以在图形中灵活地访问数据。
In Figure 2, the descriptor for the table node and the descriptor for the TBSCAN node are shown to the left of the access path graph.
在图2中，表节点的描述符和TBSCAN节点的描述符显示在访问路径图的左侧。
After creating the three new indexes, you get the new access plan graph shown in Figure 13.
创建三个新索引之后，您图13中的新访问计划图。
The SQL statement in Listing 5 creates the access path graph shown in Figure 5.
清单5中的sql语句创建如图5所示的访问路径图。
The SQL statement in Listing 4 creates the access path graph shown in Figure 4.
清单4中的sql语句创建如图4所示的访问路径图。
The SQL statement in Listing 6 creates the access path graph shown in Figure 6.
清单6中的sql语句创建如图6所示的访问路径图。
The SQL statement in Listing 8 creates the access path graph shown in Figure 8.
清单8中的sql语句创建如图8所示的访问路径图。
The SQL statement in Listing 3 creates the access path graph shown in Figure 3.
清单3中的SQL语句创建如图 3所示的访问路径图
Basically, when an SDO client needs to retrieve data, it USES the DMS to require a data graph. The DMS manages the data source access and creates a graph with the information received.
基本上，当一个SDO客户机需要检索数据时，它使用DMS来请求数据图，DMS负责管理对数据源的访问，并根据接收到的信息来创建一个图，通常这个图是一个分层的树结构，其中包含了几个数据对象。
The description of each operation includes a Query Tuner access path graph that explains its operational semantics.
每一个操作的描述都包括一个解释其操作语义的QueryTuner访问路径图。
From the access plan graph in Figure 6, you can do some initial performance analysis.
在图6的访问计划图中，您可以做一些初始性能分析。
Since Neo4j is a database, each access to the graph structure - read, write, and traversal - are managed by an ACID transaction system.
由于Neo4j是个数据库，因此对图形结构的访问——读、写及遍历都是通过ACID事务系统进行管理的。
Similarly, the last leg in the access path graph is evaluated eight times, once for each record produced by the first NLJOIN node.
同样，访问路径图的最后一步要评估8次，通过第一个NLJOIN节点产生的每条记录都要评估一次。
From this new access plan graph, you can see the following.
在这张新访问计划图中，您可以看到以下内容。
So far, you've seen how you can analyze and tune a problem query with the assistance of Optim query Tuner capabilities, such as query annotation, access plan graph, and so on.
到目前为止，您已经看到如何在OptimQueryTuner各项功能的帮助下分析和调优问题查询，这些功能包括查询注释、访问计划图等等。
From the access plan graph in Figure 6, you can see the following.
在图6中访问计划图中，您可以看到以下内容。
Applications can traverse the graph using the generic SDO API, they can access data using the object model defined by the content model, or they can use XPath to extract data from a DataGraph.
应用程序可以使用普通的SDOAPI遍历图形，它们可以使用由内容模型定义的对象模型访问数据，或者使用XPath从DataGraph中提取数据。
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