Oracle Query Rewrite

We want to do not only write SQL, but also to do a good performance of the SQL, the following for the author to learn, extract, and summarized part of the information to share with you! (1) Select the most efficient table name order (valid only in the Rule-based optimizer): The ORACLE parser processes the table names in the FROM clause in Right-to-left order, and the last table in the FROM clause (the underlying table driving tables) is processed first, In the case where multiple tables are included in the FROM clause, you must select the table with the least number of records as the underlying table. If...

In recent years, with the continuous innovation and development of the Internet industry, batch after group of websites or be eliminated or stand out, for those successful websites, most of them already exist nearly 10 or more than 10 years, in such a long period of development, in addition to the business facing the challenges, Technically, it's also a lot of challenges. The following selected Alexa rankings of the previous site (ranking up to April 21, 2012, by analyzing how they are technically coping with the challenges of business development process, to a deeper understanding of the development of the Internet industry in recent years. ...

March 13, 2014, CSDN online training in the first phase of the "use of Sql-on-hadoop to build Internet Data Warehouse and Business intelligence System" successfully concluded, the trainer is from the United States network of Liang, 　　In the training, Liang shares the current business needs and solutions of data warehousing and business intelligence systems in the Internet domain, Sql-on-hadoop product principles, usage scenarios, architectures, advantages and disadvantages, and performance optimization. CSDN Online training is designed for the vast number of technical practitioners ready online real-time interactive technology training, inviting ...

The scalability of the system is the main reason for promoting the development of NoSQL movement, including distributed system coordination, failover, resource management and many other features. That makes NoSQL sound like a big basket that can be stuffed with anything. Although the NoSQL movement does not bring fundamental technological changes to distributed data processing, it still leads to extensive research and practice on protocols and algorithms. It is through these attempts to gradually summarize some effective database construction methods. In this article, I will focus on the NoSQL database distributed special ...

The scalability of the system is the main reason for promoting the development of NoSQL movement, including distributed system coordination, failover, resource management and many other features. That makes NoSQL sound like a big basket that can be stuffed with anything. Although the NoSQL movement does not bring fundamental technological changes to distributed data processing, it still leads to extensive research and practice on protocols and algorithms. It is through these attempts to gradually summarize some effective database construction methods. In this article, I will focus on the distributed features of the NoSQL database ...