nosql database use cases

Label:　　In many cases, the application needs to implement the Excel data import function, the data if only dozens of, or hundreds, even thousands, the speed is OK. But not only that, if the customer provides you with the Excel itself has duplicate data, or some of the data in Excel already exists in the database, then, before inserting data into the database you

Last week wrote an article, database aspects of interview skills, how to display their ability from the table, courtesy of the administrator to lift, put in the home, but also thanks to you love, two days in the harvest of nearly 770 clicks, also once entered the 48-hour hot list.In order to thank the Administrator and everyone for their support, and then based on my interview experience, an original article on how the index to promote their own artic

password mysql>grantall privilegeson*.*to ' user_name ' @ ' localhost ' identifiedby ' password ' ; Format:grantselecton Database .*to user name @ Login host identifiedby password Remove authorization: MysQl>revokeallprivilegeson*.*from[emailprotected] "%"; mysql>deletefromuserwhereuser= "root" andhost= "%"; mysql>flushprivileges; Renaming tables: mysql>altertablet1renamet2; Backup: Mysqldump-hhostname-uusername-ppassworddatabasename>backup.sql ;

speed, but too many indexes affect the input write.Some habits of using tables1. As we write Java programs, we can use the Apache Commons Toolkit, the use of Oracle's own internal functions can not only improve the development efficiency, but also improve the efficiency of SQL statement execution;2. Try to write SQL statements as dm=? , and then assign a value instead of direct dm=9, so that Oracle compile

Original link: http://www.2cto.com/database/201303/195303.html, Mysqlslap introduction Mysqlslap MySQL5.1 is a benchmark benchmark tool, similar to the Apache Bench load generation tool, generates schema, loads data, executes Benckmark and queries data, and is simple, flexible and easy to use. The tool can simulate multiple clients concurrently issuing query updates to the server, giving performance test da

what is a MySQL subquery? subqueries, also called internal queries, are called external queries, as opposed to internal queries, which contain internal queries. Subqueries allow a query to be nested within another query. MySQL Database subquery features: Any place where an expression can be used, you can use a subquery, as long as he returns a single value, the subquery by the number of return values, the