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Comparison of file databases and relational databases Abstract: With the continuous expansion of application fields and multimedia technology, people have found many limitations and deficiencies in relational databases, so the database technology has entered the post-relational database era. The file database came into being. This document compares the number of

connect to them using a network cable. It is best to disable the simulator so that only one device exists in the devices list.2. sqlite3 operation When the following operations are performed, only one device is allowed in the Database List. Otherwise, an error is returned. The disconnect command can be used to disconnect the POs server. If the simulator is disconnected, it is directly disabled. Use the fol

Label:MySQL links, viewing databases, working with databases, viewing tables mysql> show databases; +--------------------+ | Database | +--------------------+ | Information_schema | | MySQL | | Performance_schema | | QQ | | Test | +--------------------+ 5 rows in Set (0.06 sec) mysql> use QQ; Database changed mysql> desc QQ; ERROR 1146 (42S02): Table ' qq.qq ' do

Detaching a database Database separation refers to the separation of databases from the server. When the SQL server is running, it maintains information about all databases, including the databases that are currently not used. If these databases are not used for the time being, running them will only increase the burd

MySql processes databases and tables, and MySql processes databases. View Database It is usually useful to obtain the Database List on the server. Run the show databases command. Mysql> show databases; Create a database Mysql> create database db_test;Query OK, 1 row aff

Four isolation levels for mysql Databases and four isolation levels for mysql Databases I recently read the high-performance MYSQL book, so I have been impressed by its examples. The transaction operation of the database is actually a group of atomic operations. Either all operations are successful or all operations fail. 　　 For example, if I want to sell a movie ticket externally and register the sales inf

relational databases and NoSQL databases what is NoSQLHave you ever heard of "NoSQL"? In recent years, this word has been of great concern. To see the word "NoSQL," you might mistakenly think it was "no! SQL "abbreviation, and deeply outraged:" How can SQL be unnecessary? " "But in fact, it is the abbreviation for" not only SQL ". Its meaning is: the application of relational database when the use of relati

Use shell to automatically back up mysql Databases and shellmysql databases at regular intervals #! /Bin/bashid = "root" # username pwd = "123456" # password dbs = "blog.ewsd.cn dangjian.ewsd.cn idc.ewsd.cn shangfa.ewsd.cn" # list of database names, separate multiple databases with spaces. backuppath = "/home/mysqlback

The path to installing and detaching Oracle databases: The Path to oracle databases ========================================================== ============================================== ====================================== 1. If there are two files when installing the database, you need to merge the two files before installing After both files are decompressed, 1of2 contains the installation file and

The performance of relational databases is very high, but it is a general-purpose database and cannot fully adapt to all purposes. Specifically, it is not good at the following processing: writing a large amount of data. When an index or schema change field is not fixed for a table with data updates, the application must quickly return results for simple queries (1) handling a large amount of data The performance of relational