删除无用的连接操作之后的查询。
现在，有多少种方法可以用来执行这个连接操作？
确保查询中进行连接操作的列都有索引。
Ensure that columns that are joined in queries have indexes.
与连接操作对应的函数是数据库关闭函数。
A complementary function to the connect operation is the database close function.
连接操作的优化算法一直都是人们研究和探讨的热点。
The optimized query of the join operation has been hot point of people study and discuss all through.
在XML数据查询中，结构连接操作占用了大量时间。
As the core operation in XML query processing, structural joining consumes a great deal of time.
在执行实际的连接操作之前，优化器使用统计数据制定一个查询计划。
The optimizer would chalk out a query plan before performing the actual join operation itself by making use of the statistical data.
主要是用连接操作，左右外链，内联。例如：学员—班级。
连接操作会首先将字符串连接在一起，然后将其作为一个参数打印。
Concatenation would concatenate the string and print it as one argument.
与轮辐式一样，可以将服务部署到分支以支持具有单点回退功能的中心连接操作。
As in hub and Spokes, services may be deployed into the branches to support hub-connected operation with a stand-alone fallback capability.
连接操作可能要消耗大量的资源和时间，这取决于表的数量以及这些表各自的长度。
Depending upon the number of tables and their respective sizes, a join operation can be very resource intensive and time consuming.
如果这个bug还在的话，那么您可以为离线连接操作指定一个或多个列作为匹配列。
If it were working, you would be able to specify one or more columns as the matching columns for an offline join operation.
例如，在事件处理程序中，可以对随异步请求一同传递的数据执行计算或字符串连接操作。
For example, within the event handler, calculation can be performed or strings concatenated for data sent along with the asynchronous request.
rope版本的连接操作则只是创建一个新的连接节点，这是个o(1)操作。
The rope counterpart simply creates a new concatenation node, which is an o (1) operation.
图4展示了具有绑定的规则，它涉及来自多个表的列，这导致了在连接操作之后进行抽样。
Figure 4 shows a rule with bindings that involve columns coming from more than one table, which causes the sampling to be done after the join operation.
本文讨论了如何在面向对象模型中引入连接操作，包括其形式、特点和实现方面。
This paper deals with the introduction of join operation into object-oriented data model, including its format, characteristics and implementation.
重写阶段将使用四个昵称上定义的引用约束和检查约束来删除连接操作和一个UNION分支。
The rewrite phase will use the referential and check constraints defined on the four nicknames to eliminate the join operations and one of the UNION branches.
该操作符提取账户id值，以驱动一个连接操作，该连接操作可以产生所需的结果集。
This operator extracts account ID values to drive a join operation that can produce the desired result set.
但是在这样做之前，我们先来演示一下断开与数据库的连接然后执行离线连接操作的能力。
But before we do, this, we will demonstrate the ability of being able to disconnect from the database to perform an offline join operation.
为了加速路径表达式处理，基于路径分解和结构连接操作的处理策略需要更深入的研究。
To facilitate path expression processing, the processing strategy based on path decomposition and structural join operation needs to be investigated more deeply.
作为XML查询处理的核心操作，结构连接操作的高效实现是提高查询处理效率的关键。
As the core operation of XML query processing, the efficient implementation of structural join is the key to improve XML query processing.
在这种情况下，在任何时候，union 所有分支上的连接操作中只有一个连接操作是活动的。
So in this case, exactly one of the joins that comprise the legs of the union is active at any given time.
LSEQ编码通过记录非叶节点的路径，在节点查询中避免了结构连接操作，提高了查询效率。
Through storing the path of internal nodes, LSEQ enhanced querying efficiency and avoided structure-joining.
String版本的连接操作要求将需要连接的两个字符串复制到新位置，这是一种O (n)操作。
The string version of concatenation requires strings you want to join to be copied to a new location, which is an o (n) operation.
和UNION操作符一样，连接操作符本身是同步的，每次只能处理来自连接操作符某一个分支的输入。
As with the UNION operator, the join operator itself remains synchronous and is only able to process input from one leg of the join at a time.
Database类的主要目的就是封装这个字符串，还有建立连接操作时可能需要的任何用户名／密码信息。
The main purpose of the Database class is to encapsulate this string, as well as any username/password information that might be needed to make a connection.
这个查询会执行一个外连接操作，以便比较从 1 月份至 11 月份的10 个特殊商店的销售信息。
This query performs an outer join to compare the sales information for 10 particular stores for January and November.
面积直方图描述了图像中基于面积的尺度分布，能够用来分析基于连接操作子处理的图像或图像的面积尺度空间。
The area histogram describes area-based scales distribution in image and can be used to analyze image processed by connected operators or in scale space.
为了简化各种数据库连接操作，jdbcURL被编码为jdbc：derby，并且根据所需的操作附加不同的后缀。
To simplify the different database-connection operations, the JDBC URL is encoded as JDBC: Derby, and different suffixes are appended based on the required operations.
在分布式数据查询处理中，连接操作是最常用的、费时的而且代价较高的一种操作，也是影响查询效率的关键因素。
In processing of distribute data query, the join operation is the kind of the most in common use, time-consuming, higher price, and also is the key factor of the query efficiency for affect.
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