Fastest Way To Learn Sql

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...

With the rise of internet web2.0 websites, the relational database has become a very hot new field, the development of the non relational database products is very rapid. 　　But the traditional relational database in dealing with web2.0 website, especially the super large-scale and high concurrent SNS type web2.0 pure dynamic website already appeared to be powerless, has exposed many insurmountable problems, for example: 1, high configured--to the database higher concurrent reads and writes the demand WEB2.0 website to be based on user personalized information to generate real-time dynamic ...

SME network security guidelines. [Theory] As the training site said, the enterprise's network security is a system, do all aspects of what is a major project, even if only a branch of network security also takes a long time to build, so in the early need to resolve the current main contradictions (ie "Stop bleeding" and control most of the risks in the first place). Based on the past experience of several of our people, we suggest that you have the following key positions in the control, you can achieve more with less effort immediate effect: 1) port control. All server non-business ports are all closed to the internet, managing ...

"Csdn Live Report" December 2014 12-14th, sponsored by the China Computer Society (CCF), CCF large data expert committee contractor, the Chinese Academy of Sciences and CSDN jointly co-organized to promote large data research, application and industrial development as the main theme of the 2014 China Data Technology Conference (big Data Marvell Conference 2014,BDTC 2014) and the second session of the CCF Grand Symposium was opened at Crowne Plaza Hotel, New Yunnan, Beijing. 2014 China Large data Technology conference ...

Intermediary transaction SEO diagnosis Taobao Guest Cloud mainframe technology Hall in fact, when I was a freshman in college, I felt that the Internet would be a part of our generation's life. This part is like television for our parents, newspaper for our grandparents. 　　In the information age, the network undoubtedly plays the most important role. March 18, 2005, the second semester of the university, I purchased the first domain name: [minyao.cn]. Yes, [Minyao] is the Hanyu Pinyin "ballad". Because I like music, also write songs, but ...

Large Data Practitioner Market status: A huge gap in pay growth in the big data age, businesses are fighting to attract and retain professionals in business intelligence and information management. Large data workers face a huge gap in the payroll survey of IT employees published every year in InformationWeek. Today's large data presents a "4V + 1C" feature. Produced: generally includes the structure, the semi-structured and the unstructured and so on many kinds of data, and they processing and the analysis way has the difference; Volume: through various ...

Six years after Google first proposed the concept of "cloud computing" (Cloud Computing), cloud computing has not only launched a new round of it competitions around the world, but has also spread across the sea in China. In particular, through the first year of China's cloud computing 2012, not only the Ministry of Science and Technology issued a ministerial-level cloud planning "China Cloud Technology Development" Twelve-Five "Special Plan", the cloud computing development to a new height, and there are several predicted, during the "Twelve-Five" period (2011 ~2015 years), Domestic cloud computing industry chain scale up to 75 ...