In the second video, PLINQ is introduced.
第二个视频介绍了PLINQ。
Therefore, PLINQ does not automatically parallelize every query.
因此，PLINQ并不会自动平行处理每个查询。
When it finds such shapes, PLINQ by default falls back to sequential mode.
当PLINQ 发现这类型态时，它预设就会回到循序模式。
IN most cases, you do not have to specify a merge option for a PLINQ query.
大部分情况下，您不需要指定PLINQ查询的合并选项。
However, after the array is populated, PLINQ can process it in parallel very quickly.
不过，在填入阵列之后，PLINQ就会平行、非常快速地处理它。
PLINQ will always attempt to execute a query at least as fast as the query would run sequentially.
PLINQ一直会尝试以至少和循序查询一样快的速度执行查询。
PLINQ is a declarative model for performing data parallel queries against XML and in-memory objects.
PLINQ是一个对XML和内存对象进行并行查询的声明式的模型。
To achieve speedup, a PLINQ query must have enough delightfully parallel work to offset the overhead.
为了实现加速，PLINQ查询必须具有足够的适合并行工作来弥补开销。
In some cases, a PLINQ query over an indexable source collection may result in an unbalanced work load.
在某些情况下，针对可建立索引的源集合进行的PLINQ查询可能会产生不平衡的工作负载。
Conversely, small source collections with trivial delegates are generally not good candidates for PLINQ.
相反，包含无关紧要委托的小型源集合通常不适合于PLINQ。
However, in some cases you may know more about your query than PLINQ is able to determine from its analysis.
不过，有时候相较于PLINQ从分析结果来做判断，您可能还比较了解您自己的查询。
This example shows how to specify the merge options that will apply to all subsequent operators in a PLINQ query.
此范例说明如何指定会套用至PLINQ查询中所有后续运算子的合并选项。
Based on this analysis, PLINQ in the default execution mode may decide to execute some or all of the query sequentially.
根据这项分析，在预设执行模式下的PLINQ可能会决定以循序方式执行局部或整个查询。
If the delegate is very expensive, then PLINQ might offer significant speedup with only a few items in the source collection.
如果委派的成本非常高，则来源集合中只要有少数项目，PLINQ就能提供极高的加速效果。
In other words, it indicates how PLINQ should merge the results from the various partitions back into a single result sequence.
换言之，它指示PLINQ如何将多个分区的结果合并回单个结果序列。
This article provides information that will help you write PLINQ queries that are as efficient as possible while still yielding correct results.
本文提供的资讯可协助您撰写尽可能有效的PLINQ查询，同时仍维持让查询产生正确的结果。
Just like code that targets the Task Parallel Library, PLINQ queries scale in the degree of concurrency based on the capabilities of the host computer.
就像面向任务并行库的代码一样，PLINQ查询会根据主计算机的能力按比例调整并发程度。
PLINQ performs best when it is allowed to process elements in the source collection in any order, and pass them to the next operator as soon as they are ready.
如果允许按任意顺序处理源集合中的元素，并在这些元素就绪时立即将它们传递到下一个运算符，则PLINQ的性能最佳。
Use this flag in cases where you know that parallel execution of the query will result in speedup, but PLINQ in the Default mode would execute it as sequential.
如果认为并行执行查询将带来加速，则使用此标志，但处于默认模式的PLINQ将按顺序执行它。
And even with queries that are entirely delightfully parallel, PLINQ must still partition the data source and schedule the work on the threads, and usually merge the results when the query completes.
并且，即使对于完全适合并行的查询，PLINQ也仍然必须对数据源进行分区并针对线程安排工作，并通常在查询完成时合并结果。
And even with queries that are entirely delightfully parallel, PLINQ must still partition the data source and schedule the work on the threads, and usually merge the results when the query completes.
并且，即使对于完全适合并行的查询，PLINQ也仍然必须对数据源进行分区并针对线程安排工作，并通常在查询完成时合并结果。
应用推荐