Oracle Sql Rollback

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 ...

NoSQL systems generally advertise a feature that is good performance and then why? relational database has developed for so many years, various optimization work has been done very deep, nosql system is generally absorbing relational database technology, and then, in the end what is the constraints on the performance of relational database? We look at this problem from the perspective of http://www.aliyun.com/zixun/aggregation/9344.html "> System design." 1, index support. Relational data ...

After more than eight years of practice, from Taobao's collection business to today to support all of Alipay's core business, and in the annual "Double Eleven Singles Day" continue to create a world record for the transaction database peak processing capacity.

In the past few years, relational databases have been the only choice for data persistence, and data workers are considering only filtering in these traditional databases, such as SQL Server, Oracle, or MySQL. Even make some default choices, such as using. NET will typically choose SQL Server, and Java may be biased toward Oracle,ruby, Mysql,python is PostgreSQL or MySQL, and so on. The reason is simple: In the past a long time, the relational database is robust ...

My Chinese name is Yu Zhihong. In the HBase community, more people know about Ted Yu. has been a member of the HBase PMC since June 2011. At the HBTC 2012 conference, I was pleasantly surprised by the wide adoption of hbase in China. Famous companies such as Taobao, Huawei, Intel and IBM all recognise HBase. HBase has become a de facto nosql solution in the United States, a trend that is more pronounced in China. I am delighted to see the company's contribution to HBase. In the introduction NoSQL ...

Amazon lead the cloud market Microsoft play affinity card This week for Amazon, it should be "a year of mixed feelings." First of all, AWS's first market training event in China kicked off in Beijing. Nearly 400 participants from all over the country gathered for the venue to open the "AWS China" sign. The second happy event for AWS is that the latest Public Cloud survey from RightScale research shows that AWS has a 54% surveyor usage rate, far behind Rac ...