本文讨论了在流水线机上编译系统的表达式优化。
This paper studies expression optimization in compilers for pipeline computers.
浏览下面这篇文章——如何使用正则表达式优化查询并节约时间？
Navigate to the link to the following article - How to use regular expression to search better and save time?
修剪字符串不是一个常见的性能瓶颈，但作为学习正则表达式优化的例子有多种实现方法。
Trimming strings is not a common performance bottleneck, but it serves as a decent case study for regex optimization since there are a variety of ways to implement it.
作为转换的一部分，优化器还决定正确的表联接顺序，重写表达式，并从SQL中消除任何冗余。
As part of the transformation, the optimizer also determines the correct table join order, rewrites expressions, and eliminates any redundancy from the SQL.
当然，如果您选择编写同时包括XQuery和SQL表达式的“双语(bilingual)”查询，那么DB 2同样会处理和优化这些查询。
Of course, if you choose to write bilingual queries that include both XQuery and SQL expressions, DB2 will process and optimize these queries, too.
在函数型语言中已经广泛使用的表达式减少的概念，而且此概念特别适用于优化语言，如XPath。
The concept of expression reduction is widely used in functional languages, and is particularly appropriate for optimizing a language such as XPath.
这种信息非常有价值，因为可以构造出能够通过常量叠算(constant folding)优化的表达式。
This is valuable information because you can construct expressions that can be optimized through constant folding.
清单23中的优化概要文件包含一个XQuery表达式，它为经营软件并以日元交易的公司返回客户帐户信息。
The optimization profile in Listing 23 contains an XQuery expression that returns customer account information for companies that deal in software and trade in Yen currency.
当谈到解析器生成器的时候，解析表达式语法（PEG）最近因为一篇BryanFord介绍的一种叫做“Packrat解析”优化的论文而变得很流行。
When it comes to parser generators, Parsing Expression Grammars (PEG) have become quite popular recently after a thesis by Bryan Ford introduced an optimization called "Packrat Parsing".
清单5中第二行调用对rope进行修饰，优化正则表达式匹配。
The call on the second line in Listing 5 decorates the rope to optimize regular-expression matching.
注意：当索引表达式被用于关系表达式，或作为某个操作符类函数的参数时，查询优化器将考虑使用函数索引。
Note: the query optimizer considers using a functional index when the index expression is used in a relational expression or as an argument to one of the operator class functions.
XPathExpression对象是原来的XPathString的编译表示，代表XPath表达式在内部的、经过优化的表示。
XPathExpression objects are compiled representations of the original XPath String; they represent internal, optimized representations of the XPath expression.
本文主要对XML数据库的查询语言、XML数据路径表达式查询的优化技术和XML数据的查询处理技术进行了重点研究。
This paper focuses on the query language of XML data, the technologies of path expression optimizing and the query processing of XML data.
如果发现表达式是常量，那么就使用可以优化的常量表达式。
If the expression can be verified as a constant, then a constant expression (which is available for optimization) is used.
通过表达式求值的编译执行和代码优化等手段，较好地解决了大数据量的处理问题。
Large data processing was relatively well solved by means of compiling and running of expression evaluation and code optimization.
文章给出了约束资本预算优化模型的一般数学表达式。
This paper provides the general mathematics formula of constraint optimization model of capital budgeting.
上面表达式使优化器不能有效分配基数或选择性消耗，可能会反过来影响整个执行计划。
These expressions prevent the optimizer from assigning valid cardinality or selectivity estimates and can in turn affect the overall plan and the join method.
最小的控制界优化数学模型，最后给出主要研究过程、最优控制下限的数学表达式及其适用条件。
Major parts of the researching process, the formula for the optical control limits and the application condi.
针对DBMS查询优化器如何生成成本最小的查询计划问题，给出关系代数表达式的优化规则。
Aiming at how the DBMS query optimizer to generate the smallest cost query plan, optimization rules of the relational algebra expression are given.
用反步设计思想获得具有待定参数的控制器表达式，然后用预测控制在线优化获得控制器的参数。
The controller expression with undetermined parameters can be acquired by using backstepping design idea, and the controller parameters are optimized online by using model predictive control.
为了得到通用的优化模型，对动压轴承型线数学表达式的本质特点进行了研究。
In order to obtain a general optimization model, study on substantial characteristics of the mathematical expression of hydrodynamic bearings profiles was brought forward.
因为循环检查字符是不是空格在效率上不如正则表达式所使用的优化过的搜索代码。
That's because looping over characters to check whether they are whitespace can't match the efficiency of a regex's optimized search code.
在自由电荷传输模型的基础上得到了电荷耦合器件电荷传输效率的表达式，编制了电荷耦合器件电荷传输效率优化设计软件。
Based on the free charge transfer model the expression of the charge transfer efficiency in CCD is obtained, and the software for improving the charge transfer efficiency in CCD is programmed.
所获数学表达式可为该类传感器的优化设计提供理论依据。
The mathematical expressions obtained provide theory basis for the optimum design of this type sensor.
每种浏览器的正则表达式引擎也有不同的内部优化。
Each browser's regex engine also has different internal optimizations.
运用拉格朗日乘数法，以最大制冷量为优化目标，对该系统进行了优化，得到最大制冷量的一般表达式。
Applying the method of Lagrange multiplier, the system is optimized for maximum cooling rate and gets the rate general expression.
与传统的方法相比，该法物理概念清楚，表达式简单明了，计算结果精确，便于电算和优化设计。
Compared with the traditional method, the new one is clear in physical conception, simple in expression, accurate in calculation, and convenient for computer operation as for optimum design.
小外径的电涡流传感器薄线圈的参数优化设计的关键是寻求合理的目标函数的表达式。
The key of the optimization design of a small eddy current sensor coil is to find out the reasonable expression of the optimization destination function.
然后以近似表达式为代价函数，提出一种优化感测时间和功率分配方案。
And then an optimum sensing time and transmitted power allocation was proposed by making use of the approximate outage probability formulation as cost function.
通过挠度的解析表达式，可获得这种爆炸加工的动态响应特性，为工程实践中优化参数和动态分析提供了有效工具。
The response characteristics in the cladding process can be obtained by the mathematic expression of flexibility of girder and an effective stool has been provided...
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