表

Bitmap indexes include rows that have NULL values, unlike most other types of indexes. Indexing of nulls can be useful for some types of SQL statements, such as queries with the aggregate function COUNT.SELECT COUNT FROM employees

对于select count from tab，全表扫描比使用索引效率要高，经过分析的表cbo会倾向于使用索引，这是oracle软件的判断问题，最好还是不要收集统计信息，让oracle执行全表扫描。

By statistics and sample data, and taking the speedometers of Shanghai Santana LX cars as the target, the test values were statistically analyzed to get the distribution parameters and to establish the corresponding mathematical models. From this study, the statistic rule of the indicatory error could be well known. It is beneficial for safe drive and is significant in improving the design of the speedometer.

本文运用数理统计工具及样本实测数据，选取上海桑塔纳LX轿车车速表检验值进行统计规律研究，给出其分布参数，建立相应数学模型，指明其误差情况，对于深入了解轿车车速表指示误差统计规律，保证车辆的行驶安全性，改进车速表设计均具有十分重要的意义。

Within the design strategy, a GPRS terminal is connected to the Intemet via the GPRS network, and communications between the meter and client in the AMRS center is implemented by the communication protocol in the GPRS remote AMRS. After practical testing, it indicates that this GPRS TE is characterized with good real-time, high reliability and inexpensiveness.

系统的基本设计思想是将GPRS终端经由GPRS网络接入Internet，按照GPRS远程抄表系统中制定的通信规约，实现表计和抄表系统管理中心的客户端之间数据和命令的信息传输。

In chapter 2, we consider the isomorphisms of integral table algebras. For integral table algebras with integral table basis B we can consider integral R-algebra RB over a subring R of 〓, the ring of the algebraic integers.

第二章 我们考虑了有理整表代数间的同构问题：对任意整表基为B的整表代数，我们研究了代数整数环〓的一个子环R上的整R-代数RB。

For integral table algebras with integral table basis B we can consider integral R-algebra RB over a subring R of 〓, the ring of the algebraic integers.

第二章 我们考虑了有理整表代数间的同构问题：对任意整表基为B的整表代数，我们研究了代数整数环〓的一个子环R上的整R-代数RB。

When the program module read the temporary integral table, it up dated the integral table, the user condition table, the integral reward data sheet th

程序模块读取临时积分表，通过返回临时积分表的数据对积分表，用户状态表，积分奖励记录表进行更新，并对积分累积记录表进行更新，系统着重于对更新失败和程序异常时进行处理。

It implements a sorted list of adjusted timeouts such that the interrupt handler is only decrementing the first element at all times.

它是一个排过序的链表且链表中的超时设定都是调整过的，这样中断处理过程就只需要递减链表中第一个元素的计数器即可。

It's also important that you understand how the virtual function table works, so you understand the extra steps that can decrease performance that take place when you call a virtual function (each object has a virtual function table pointer hidden from you in its structure data , and to call a virtual function, you need to follow that pointer to the table, and then jump to the function pointer contained within, which can hurt caching).

理解虚函数表是如何工作的也同样重要，这样你就能够理解当你调用虚函数时需要的额外步骤，这些步骤会降低性能(每个对象都有一个隐藏的虚函数表指针，这样调用一个虚函数，你需要根据这个指针找到那个函数表，然后跳到它所包含的函数指针所指的函数里，这会降低cache的效果)。

Department of Judicial Information, Shandong Politico-legality Institute,Ji′nan 250014,China摘要: This paper presents a solution using GPRS to remote reading electric kilowatt-hour meter, aiming at the shortcoming of human reading meter in power system such as expand more people and more time, low reliability and data is not real time.

针对目前电力系统中人工抄表费时费力，可靠性和实时性差等缺点，提出了使用GPRS作为传输方式的电能表无线抄表方案。

There were three major findings.(1) On the basis of the assessment of overall model fit and parameter estimates, the hypothesized second-order confirmatory factor analysis model represented an adequate fit to the sample data.(2) According to the cross-validation analysis, the second-order factorial validity of this scale was very stable.(3) This hypothesized model was invariance across these five important demographical variables, including school, gender, grade, right/left-handedness, and past experience in unintentional injury, via the testing of invariance in the multiple groups.

结果有三项主要的发现：第一、经整体暨个别的残差分析、整体模式之适配与其取代指标，以及估计参数之统计考验等结果，均指出假设此量表为二阶因素分析测量模式是相当恰当的；第二、经交互确认效度分析结果，显示此量表之二阶潜在因素结构是非常稳定；第三、经多组别不变量统计考验结果，指出此量表之二阶潜在因素结构，对於学校别、性别、年级、用手习惯，以及过去伤害经验这些社会人口变项，大致上具有因素个数、因素负荷量、因素变异数，以及测量误差变异数等不变量的特性。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。