Oracle Unique Index

As an outstanding representative of the Object relational database, Oracle is undoubtedly the most powerful. Whether it's the size of the database, the support of multimedia data types, the parallelism of SQL operations replication, or the security services, Oracle is much stronger than Sybase, Informix, Added to the latest version of the Oracle8.0.4 is to enhance the characteristics of this, but also introduced a number of new features, such as: Data partitioning (partitioning), Object-relational technology (objects relational T ...

The logical design of database is a very broad problem. In this paper, the main key design of the table is discussed in the design of MS SQL Server, and the corresponding solutions are given. Primary key design status and problems about database table primary key design, in general, based on business requirements, based on business logic, the formation of primary key. For example, when sales to record sales, generally need two tables, one is the summary description of the sales list, records such as sales number, the total amount of a class of cases, and the other table record of each commodity ...

Affirmation: The article is longer, if you are the industry webmaster please read carefully, welcome to join the industry webmaster QQ Group: 37466050 (using the invitation mechanism, add please specify the URL.) The rise of the industry web site has become an unstoppable trend in China's e-commerce development, according to a survey of 07 growth rate is expected to be close to 50%. For many industry websites, after a period of development, to seize the opportunity to win a certain market share. 　　At the same time, will face many new challenges, the market competition will become more and more fierce. Compared with the Internet companies that have VC support ...

This ranking is based on the DB engines list, which analyses 200 different databases on the market, listing top 10. The undisputed top 3 Oracle, MySQL, and Microsoft SQL Server have all along been occupying the first three of the rankings with an absolute advantage, carving out the largest number of users in the market with unique advantages. 1. Oracle 11g First release: 1980 Licensing mechanism: Proprietary SQL: Yes ...

According to a report published last month by IDC (International Data Company), sales of large data technology and services are expected to grow from $3.2 billion trillion in 2010 to $16.9 billion in 2015, with an annual growth rate of 7 times times the average it market. The McKinsey Global Institute points out that data is becoming a factor in products such as physical capital and human capital. Companies that can take advantage of big data will defy the data. Data capital will be as important as brand capital. Business is already adapting to big data, and the data revolution is disrupting already-established industries and business models. No matter ...

Intermediary transaction SEO diagnosis Taobao guest Cloud host technology Hall Jerry Yang 1967 born monkey Online business opportunities, the wise to beat; Yahoo! What is the meaning? 　　Who is the largest media company in the world? Ph. D., a PhD student in the Department of Electronic Engineering at Stanford University, is a fellow of the same profession; his name is Jerry Yang, a few years ago with nothing, now a billionaire; Reuters and Yahoo Hand, Jerry Yang said, do this work, there is a feeling of jumping off the cliff;

In 2017, the double eleven refreshed the record again. The transaction created a peak of 325,000 pens/second and a peak payment of 256,000 pens/second. Such transactions and payment records will form a real-time order feed data stream, which will be imported into the active service system of the data operation platform.

Editor's note: Jay Kreps, a chief engineer from LinkedIn, says that logs exist almost at the time of the computer's creation, and there is a wide range of uses in addition to distributed computing or abstract distributed computing models. In this paper, he describes the principles of the log and the use of the log as a separate service to achieve data integration, real-time data processing and distributed system design. Article content is very dry, worth learning. Here's the original: I joined the LinkedIn company at an exciting time six years ago. From that time ...

Editor's note: Jay Kreps, a chief engineer from LinkedIn, says that logs exist almost at the time of the computer's creation, and there is a wide range of uses in addition to distributed computing or abstract distributed computing models. In this paper, he describes the principles of the log and the use of the log as a separate service to achieve data integration, real-time data processing and distributed system design. Article content is very dry, worth learning. Here's the original: I joined the LinkedIn company at an exciting time six years ago. From that time ...

Since 2012, large numbers have become a word from a concept and become more noticeable as time goes by, and by the year 2014, big data is clearly the star of attention in the IT circle. The "4 V", summarized by the renowned research institute IDC, can well define large data concepts, 4V respectively capacity, type, speed, and value (volume, produced, velocity, and values). 　　Large data is a new technical framework for acquiring value from large capacity data through high-speed capture, discovery and analysis. Each line ...