Oracle Left Join Example

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...

Pinch point count, graduation also nearly two years, in the two years of time, I went through a big company--my own business--to join a start-up company these three different work rhythm, in addition to the system basically all kinds of companies have been, but also have some of their own choice of work to think, and then to the graduates to find internships/job-hopping season, 　　So today, let's share my opinion. 　　Note: I am not very interested in the work within the system, so the following discussion does not involve your party's enterprises and institutions and accounts. First introduce myself to the work process, do ...

Large data processing technology is changing the current operating mode of the computer. We've got a lot of revenue from that because it's the big data processing technology that brings us search engine Google. 　　But the story is just beginning, and for several reasons, we say that large data processing technology is changing the world: * It can handle almost every type of data, whether it's microblogging, articles, emails, documents, audio, video, or other forms of data. 　　* It works very fast: practically in real time. * It's universal: because it's ...

Absrtact: Lu Zhong (left) and Haijun (right) a suit of investment meeting, the peers are showing an investment report, dressed in casual wear and haijun to see each other, we may not be able to do this life report, this can do. 　　Lu Zhong (left) and Haijun (right) a suit of investment meeting, the peers are showing an investment report, dressed in casual wear and haijun to see each other, we may not be able to do this life report, this can do. This pair from 8848 to million net again to ...

Intermediary transaction SEO diagnosis Taobao guest owners buy Cloud host technology lobby mobile Internet after the rise of online tourism can really shape. 　　   　　It is to extend the impact to the user long-term and short-term decision-making, for tourism and tourism after the market to create greater value, but also to promote their own closed-loop towards more complete and mature. 　　Another industry that is being changed by mobile Internet. Without a smartphone, Shen Zhuoli may join Oracle with Sun, which is still shuttling around the world every month.

The intermediary transaction SEO diagnoses Taobao guest Cloud host technology Hall global search engine marketing meeting Beijing station on the eve of the meeting, the General Assembly Chinese official website wins the time Network marketing portal aimed at the guest speaker conducted a series of interviews, Yu Haowi Vice President Yingwei interviewed Taipei International SEO director Lin Si. 　　The interview record is as follows: Yingwei: Think me, your customer type is small or medium-sized enterprise or big business? Lin Si: Large enterprises, the majority of the group. The Big Advertiser. Because our SEO charges are not cheap ...

Shen is the founding and executive partner of Sequoia China fund, representing Sequoia China, Shennan Peng has invested in horse sports, Qihoo Net, Li Nong Group, new source Biology, Acer dream cartoon, I want the net, Sui Cai Technology, the public insurance and the good software and serve as directors of these companies. Shen is the founder and director of Ctrip, who has long served as president and Chief financial officer of the company. He is also the founder and co-chairman of a chain hotel, such as the home hotel chain successfully landed on Nasdaq in 2006. He is also one of China's largest outdoor media companies in the media and China's largest real estate services company Easy to center ...

Method 1 delete yourtable where [id] not in (select max ([id]) from yourtable group by (name + value) b on a.id = b.id where b.id ...

It seems that the glorious era of IT companies in China is over. In the last one months, Microsoft, Nokia, Cisco, IBM, Oracle, and so on have been different degrees of layoffs. The sudden layoffs were like a bomb thrown at innocent employees. The news is really sad, but not surprising. 　　Over the years, job cuts in High-tech industries, like barbecues, pools and relaxation, have always been accompanied by vacations, and will be standard and traditional for reasons such as performance, strategic adjustment, and so on. Naturally, for the foreign employees who wholeheartedly enjoy the high salary and ease of the foreign enterprises, they will only ...