rdbms concepts

parameters of the alarm method. Solution 2: Since open, close, and alarm belong to two different concepts, they should be defined in abstract classes that represent these two concepts according to the ISP principle. The two concepts are defined by abstract class. Both concepts are defined by interface. One is defined

I. Related concepts of classes and objects 1, object-oriented and process-oriented understandingObject-oriented and process-oriented are the thinking ways to solve the problem. process oriented : Think in terms of the performer , focus on " How to do ", more suitable to solve small projectsObject-oriented : Thinking in the direction of the conductor, focusing on " who to do ", more suitable for solving large-scale projectsObject-oriented and process-o

Label:Oracle RAC Learning notes: Basic concepts and Getting Started April 19, 2010 10:39 Source: Book's Blog book Editor: Xiao Xiong【Technical Development Technical Articles】Oracle 10g Real Application Clusters introduction1. What is clusterA cluster is made up of two or more independent, network-connected servers. Several hardware vendors have been providing a variety of requirements for cluster performance over the years. Some clusters are only inte

Introduction to basic concepts and operating experimentsThe main experiments in this section are:1, experimental building environment Introduction 2, Common shell commands and shortcut keys 3, Linux use tipsI. Introduction to LINUX Desktop environmentCompared to the current Windows system, Unix/linux itself is no graphical interface, we usually see on the unix/linux distribution of the graphical interface is actually just run on the Linux system on to

RAID It means a redundant array of inexpensive disks (redundant array of inexpensive Disks), but now it is known as a redundant array of independent disks (redundant array of independent Drives). Earlier a very small disk was very expensive, but now we can buy a larger disk cheaply. Raid is a collection of disks that are put together to become a logical volume. AID contains a group or a collection or even an array. Use a set of disk-combined drives to compose a RAID array or RAID set. Connect at

Using ASP. NET 2.0 technology, creating Web custom server controls is not an easy task. Because, this requires developers to understand and be able to apply a variety of web development techniques, such as CSS stylesheets, client-side scripting language,. NET development language, server control development technology, even the hottest AJAX technology, and so on. Although the reality is so "difficult", but this development technology is not really difficult to grasp. Everything has to be done fr

Objective: In the process of learning Java, mastering the basic concepts of our learning is very important both j2se,j2ee,j2me, J2SE is the basis of Java, so it is necessary to do a summary of the basic concepts, so that everyone in the future learning process to better understand the essence of Java, Here I have summed up 30 basic concepts. Java Overview: At

For those who have just come into contact with Linux, it will definitely give Linux a bunch of different filenames to stun. Don't say, just for example, we know that the most common compressed files under Windows are only two, one is zip, the other is. rar. But Linux is different, it has. GZ,. tar.gz, Tgz, bz2,. Z,. Tar and many other compressed filenames, in addition to the. zip and. rar under Windows can also be used under Linux, but there are too few people on Linux that use. zip and. rar. Th

For those who have just come into contact, will certainly give Linux a large pile of various filenames to stun. Don't say, just for example, we know that the most common compressed files under Windows are only two, one is zip, the other is. rar. But Linux is different, it has. GZ,. tar.gz, Tgz, bz2,. Z,. Tar and many other compressed filenames, in addition to the. zip and. rar under Windows can also be used under Linux, but there are too few people on Linux that use. zip and. rar. This article w

"MicroServices Architecture" Springcloud Components and concepts Introduction (i) One: what is microservices (microservice) microservices English name Microservice, The Microservice architecture pattern is to organize the entire Web application into a series of small Web services. These small Web services can be compiled and deployed independently, and communicate with each other through their exposed API interfaces. They work together to provide fun

Author: Edison Chou Source: Blog Park publish time: 2014-09-03 15:59 read: 318 recommendations: 2 original link [favorites]　　Original Shivprasad Koirala　　English Original: Six important. NET Concepts:stack, heap, value types, reference types, boxing, and unboxing　　I. OverviewThis article explains six important concepts: heap, stack, value type, reference type, boxing, and unpacking. This article begins by explaining the changes that occur within the s

Content Guide Overview What happens behind a variable when you declare it? Heap and Stack Value types and reference types What are value types and which are reference types? Packing and unpacking Performance issues for boxing and unpacking I. OverviewThis article explains six important concepts: heap, stack, value type, reference type, boxing, and unpacking. This article begins by explaining the changes that occur within the system af

As we all know, Java ME, formerly known as J2ME (Java Platform,micro Edition), is a Java language platform for embedded consumer electronic devices such as set-top boxes, mobile phones, and PDAs, including virtual machines and a series of standardized Java APIs. Together with Java SE and Java EE, it forms the three major versions of Java technology and is also developed through the JCP (Java Community Process). There are several important concepts in

The key concepts behind regular expression advanced techniques The original English text comes from smashing Magazine. Translated by Woole. Reprint please indicate the source. Regular Expressions (Regular Expression, abbr. Regex) is powerful and can be used to find the information needed in a large string of words character. It takes advantage of the conventional character-structure expressions to function. Unfortunately, simple regular expressions

There are several important concepts in the conceptual J2ME platform, such as memory, CLDC, MIDP, and so on. Beginner J2ME often don't understand these concepts deeply, and even have deviations. The purpose of this paper is to expound the relevant important concepts in J2ME. 1. Memory We have been emphasizing that the Mobile information device memory is very sma

commandMongod "MongoDB"Start the servicenet start MongoDBTest whether the service is started, enter localhost:27017 in the browser, or the default port is 27017 if no port is specified manuallyIi. Basic Concepts 1. FeaturesMongoDB does not have some relational databases and common functions, such as connectivity and complex multi-line transactions. Omitting these features is an architectural consideration (for better extensibility) because these two

There are some basic concepts in the Mule ESB that understand these basic concepts before you can understand the internal mechanisms of Mule. We can also see the basic idea of mule to solve the problem. 4. Basic Concepts 4.1 Model Model represents the run-time environment that hosts individual services. Figure Model 4.2 Service A service is the basic unit that

Label:DB2 supports the following two types of tablespaces:1. System Management Memory table space (Sms-system MANAGED STORAGE)2. Database Management Memory table space (Dms-database MANAGED STORAGE)Comparison of characteristics of SMS and DMS user table spacesFeatures SMS DMSThe ability to dynamically increase the number of containers in a table space n yAbility to store index data in different table spaces N YAbility to store long-form (LOB) data in a separate table space n yTables can be dispe

I. Basic concepts of the databaseDynamic web site development is inseparable from data storage, data storage is inseparable from the database, database technology is an important part of computer technologies, in the field of software development plays a vital role.The so-called database can be understood as the repository used to store information. and information is to be stored down some of the data, such as the user's name, age, product price, pro

name in the database and can contain an infinite number of documents. The concept of a set is similar to that of a table in a relational database service (RDBMS). The difference is that it does not need to define any schema ).Schema-free means that we do not need to know any schema definitions for the files stored in the mongodb database. If necessary, you can store files of different structures in the same database.The document stored in the set is