Oracle If Exists

HBase as a subproject under Hadoop, the current development is more powerful, and traditional relational database Oracle to compare, both have advantages and disadvantages, we first look at a simple table. Data maintenance: For example, UPDATE, just insert a new record according to key value, the old version is still in, will be in the process of storefile merge delete data maintenance: Add and remove change is very convenient, directly modify the above simple list of hbase and Oracle the difference between the two, There are other details where there is no description, can be from above the right ...

2011, IBM has finally become a century-old shop. On birthdays, IBM published four pages of ads in the Wall Street Journal, the Washington Post and The New York Times. Our grandparents ' generation, the company that everyone admired, no longer exists. Of the top 25 companies in the world's top 500 companies in 1961, only 6 are now left. "The ad may have been designed to promote IBM's resilience and quality, but it also highlights the entrepreneurial world today, with new companies springing up like bamboo, not just in Silicon Valley but around the world," he said. ...

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...

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 ...

Shentong Express its electric business platform "Love to buy the network super" since September 20 has been unable to visit the normal, love to buy a network of less than two months to declare failure. Shentong Express President Xichunyang said, "Love to buy the net" at the beginning of the line that the product category is too miscellaneous, after the line does appear a variety of problems, so decisive stop to adjust. "(electricity) in this direction we did not give up, is currently undergoing category adjustment, want to take the boutique route." Xichunyang said there was no timetable for the "resurrection" of the love purchase. Other people familiar with the matter said, love to buy the net money from Xichunyang personal investment, the senior management from a ...

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 ...

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 ...

Now, talking about big data is not new, all walks of life are competing in the excavation of large data "great value", resulting in a wide variety of customized large data programs. On the other hand, there are large groups of "double-edged swords" that hold large data at risk. Is big data a business opportunity or a crisis? If you have to choose, I think it is business opportunities, and any business opportunities are risk factors, the risk need not blindly expand to sensational. If everyone can obtain success from the big data, then the benefit is the social overall progress, but will not change the social individual or the group's strength pattern. I think, do ...

I joined the LinkedIn company at an exciting time six years ago. From that point on, we cracked down on a single, centralized database and started switching to a special distributed System suite. This is an exciting thing: the Distributed graphics database, the distributed search backend, the Hadoop installation, and the first and second generation key value data stores that we build, deploy, and still run until today. The most rewarding thing we've learned from all of this is that the core of many of the things we build contains a simple idea: log. Sometimes ...