CODING PUSH

Photo by You X Ventures on Unsplash Index (Index) is a very important concept in relational databases . In general, index will improve query performance. For a database administrator (DBA), creating indexes for a database is a very important part of their work . Generally speaking, the index design is based on the structure of the table in the database or the logical relationship between the tables. For example, the primary-key of each table is actually an index, and the employee ID column in the EMP table that records employee information is usually also indexed. But experienced database administrators know that designing appropriate indexes is not a simple matter. In the actual production environment, program developers who write applications often do not understand database design as database administrators do, so a common situation is that SQL query statements written by program developers may not be able to use database administrators to create The index, resulting in slow databa...

Photo by  Christina Morillo  from  Pexels Use a well-defined table or column names and keep them consistent (for example, School, StudentCourse, CourseID). Use the singular form of the table name (ie, use StudentCourse instead of StudentCourses). The table represents a collection of entities and does not need to be plural. Do not use spaces in the table name. Otherwise, you will have to use characters such as "{" and "[" when defining the table (that is, in order to access the table Student Course, you have to write "Student Course". Using StudentCourse is sufficient). Do not add unnecessary prefixes or suffixes to the table name (that is, just name School, not TblSchool, SchoolTable, etc.). Encrypt the password to ensure security. You can decrypt them in the app when needed. Use integer ID fields in all tables. Even if the ID is not used right now, it will be useful in the future (for example, in the associated table, index, etc.). Use integer (or related...

With the popularity of the Windows 7 system, more and more Windows XP users have switched to Windows 7 system, but because the new system is not familiar with the process of use, maybe due to many external reasons leading to failure and problems, resulting in the computer can not be used properly. Now the small editor will be the user reflects the situation more concentrated some of the problems sorted out, for your reference:  How to resolve "The upgrades program stopped at 62% " in Windows 7 Description: Upgrade issue for WIndows 7. Vista users found that after they chose to upgrade Windows 7, the upgrade stopped at 62%. You can open the installer log file to see where the problem is. Microsoft confirmed that this issue occurred as a result of the Iphlpsvc service stopping to respond during the upgrade process. Solution: 1) Restart your computer and go back to Windows Vista; 2) Click Start, right-click My Computer, and then click Properties; 3) On the Advanced tab, click En...

1 The concept and characteristics of cloud computing  1.1 What is the cloud  Cloud computing, a popular term in the IT industry in recent years, is not a new technology, but a fusion of multi-door IT technology. This article will briefly introduce the basic concepts and characteristics of cloud computing, explore why enterprises need cloud computing and the process of building cloud computing. 1.1 What is cloud computing? Cloud computing is an internet-related service growth, usage, and delivery model that provides dynamically scalable and virtualized resources over the Internet. Simply put, cloud computing, which utilizes the transmission capabilities of the Internet to transfer data storage and processing from local servers to the Internet, is not a new technology, but a product of the convergence of traditional IT technologies such as distributed computing, parallel computing, network storage, virtualization, and so on. Cloud computing is divided into narrow cloud computing...

Amazon, Microsoft, HP, Yahoo, Intel, IBM, and other companies have announced their own "cloud plan", cloud security, cloud storage, internal cloud, external cloud, public cloud, private cloud, so what is cloud computing technology? Where are the generations, concepts, principles, applications, and prospects for cloud computing technology ... In 2006, Google launched the "Google 101 Program" and formally introduced the concept and theory of "cloud". Then Amazon, Microsoft, HP, Yahoo, Intel, IBM, and other companies have announced their own "cloud plan", cloud security, cloud storage, internal cloud, external cloud, public cloud, private cloud ... A dizzying array of concepts is constantly hitting people's nerves. So what exactly is cloud computing technology? Where are the concepts, principles, applications, and prospects for cloud computing technology? First, the development of cloud computing ideas Under the traditional model, an enterprise ...

1. What is the goal of the operating system? ​ First, the concept of the operating system is given: Operating System (OS) is the first layer of software configured on computer hardware, and is the first expansion of the hardware system. OS is a modern computer system, the most basic and most important system software, such as compilers and other software, database systems and other system software and a large number of applications are directly dependent on the support of the operating system. ​ In fact, the PCs we use daily are installed with Windows, macOS, or Linux, and the Android, IOS, or the dead Symbian installed on the mobile phone, or the emerging domestic Hongmeng OS, are specific to our lives. In China, smart TVs, refrigerators, and homes are all installed with various OSs. Operating systems have taken root around us, and everyone is accustomed to them. OS invisibly helps us manage hardware resources on the device. OS Has been essential. ​ Below we use a picture to illustrat...