Database Administrator

I am writing a software program on the Linux platform and need to use a simple database. Mysql is a good database, but its data is stored on the server. The basic function I want is to create a local database file using program C, and then perform

PS: MySQL 5.5 series has become a stable version for some time, but according to my survey, it is still dominated by the 5.1 series in the production environment. In large Chinese companies, it is only determined that Jinshan is using 5.5. Several

Code analysis is based on the latest 5.5.21 The main () of the Mysql server is in/SQL/main. cc. The actual entry point is in/SQL/mysqld. cc. We can start reading from mysqld_main () directly. First, understand some important macro definitions: (1)

If the 625 error occurs, the index memory is insufficient. You only need to increase the index memory.However, this issue is a bit special. This issue occurs during data recovery. The specific statement is as follows:Processing data in table:

1. Install MySQL database $ Yum install mysql-server.i686 See the post-Installation Process in http://dev.mysql.com/doc/refman/5.1/zh/installing.html#unix-post-installation 2.9.2 Unix 2. Start MySQL server Mysqld_safe -- user = mysql --

What is a distributed database?The data is physically stored on multiple nodes of the network, logically as a whole.Independence of distributed databases:The independence of distributed data means that users do not have to worry about how data is

The latest mysql versions require cmake compilation and installation. It is estimated that this method will be used in future versions. Therefore, we will record the installation steps and procedures for your reference. Note: This installation is

To achieve the following goals:A. Enable auto-start of Oracle instancesB. Shut down the Oracle database before shutting down the operating system or restarting the operating system. A. Follow these steps to start an oracle instance:1. modify the

1. Set this column to null and modify its type (this will cause data loss) 2. The simplest method:Assume that your table is named tab_target.Create table test as select * from tab_target whre 1 = 2;Alter table test modify (col_name number (5

MongoDB is a NoSQL database system. A database can contain multiple collections, each of which corresponds to tables in a relational database; A set of records identified by columns can be stored in each collection, and columns can be freely defined

Today, I searched for data in the Oracle database and encountered a table with a character type of CHAR [2000]. Due to the length of the character, it cannot be retrieved using String. After google Baidu found that the CLOB type can be used. The

The Table name and Schema name are the same: The schema and table names are both Arwen.Schema Arwen contains a PKG package with the Plus function. The result of adding two numbers is returned.SELECT Arwen. PKG. Plus (1, 2) FROM dual; -- no error

1. view the encoding formatShow variables like 'character % '; + -------------------------- + ---------------------------- +| Variable_name | Value |+ -------------------------- + ---------------------------- +| Character_set_client | latin1 ||

Version: hibernate-3.2.7 One method: Use uuid to generate a unique primary key. In this way, if the Object id is null, a UUID is automatically generated during storage. If the id is not null, this record is located in the database and then updated.

Oracle External combined command:The most important thing to understand (+) is that (+) is always placed on the side where information is scarce, and records on this side are displayed as null values. Example: First, preview the two tables that we

Use diagnostic file monitoring routinesI. Diagnostic filesDiagnostic files are a way to obtain information about database activities. They are used to solve database problems and contain information about important events in the database, these

MongoDB has three methods to save java objects. One is to implement the DBObject interface through a class, and the other is to use the object ing function of the spring-mongodb tool, converts a java object to the BSON document of MongoDB. One is to

1. Single master and single slave 1. the versions of the master and slave databases must be consistent. 2. on the master server, set an account for the SLAVE database and use replication slave to grant permissions. Mysql> grant replication slave on *

It is convenient to connect to the MySql server using Jdbc. First, import jdbc to the project or put jdbc into ClassPath. Here, I use Eclipse to directly import the jdbc jar file. Then, the DriverManager is developed, And the froName of the Class is

Cause: The SQL statement is as follows: Select count (*) from test; Result 1390. Select count (*) from test where bb not like '% disable %' Result 393. In the actual browsing process, it is found that the result set is not disabled and there