Database Administrator

MySQL tutorial-When AUTO_INCREMENT auto-increment encounters 0 DBAs familiar with SQL Server know that if you want to display the auto-increment values in SQL Server, except for the auto-increment columns in the INSERT statement, you also need to

Install MongoDB on CentOS7 Install MongoDB on CentOS7 1. Connect to the CentOS7 server through SecureCRT; 2. Go to the/usr/local/directory:Cd/usr/local 3. Create the tools directory in the current directory:Mkdir-p tools 4. Go to the tools directory:

Oracle Linux 5.5 (64bit) Installation of Oracle 11g R2 RAC graphic tutorial 1. Preparations before installation:Operating System: Oracle Linux 5.5 64bitCluster software: GI 11.2.0.1Database: database rdbms 11.2.0.12. Resource preparation:Oracleasm-2.

ASCII (str)Returns the ASCII value of the first character of the string 'str' (0 is returned when 'str' is an empty string)Mysql> selectASCII ('2 ');-> 50Mysql> select ASCII (2 );->50Mysql> select ASCII ('dete ');-> 100ORD (str)If the string 'str'

Oracle 11g password expired lock reported ORA-28000 the account is locked, 11gora-28000 I. Reasons for triggering this error and Related Factors This is because "PASSWORD_LIFE_TIME = 180 days" is set in the default profile in oracle11g by

Chapter 2 User Authentication, Authorization, and Security (10): Create a database that contains, authenticationSource: Workshop Without the consent of the author, no one shall be published in the form of "original" or used for commercial purposes.

Oracle10g (32, 64-bit) is successfully installed in win7 (32, 64-bit ). Win7-32-bit installation 32-bit oracle10g, win7-64 32-bit installation, 64-bit oracle10g can refer to this case. Reference:

ORACLE converts data between milliseconds and dates, and oracle converts data between milliseconds. Convert millisecond to date SELECT TO_CHAR(1406538765000 / (1000 * 60 * 60 * 24) + TO_DATE('1970-01-01 08:00:00', 'YYYY-MM-DD HH:MI:SS')

Database review 5-security and database review securityDatabase review CH7 Security 7.1 database security Introduction If integrity is a database protection measure for authorized users, security is a database protection measure for unauthorized

To solve the pressure on a single server, the database and sub-server are deployed, but the table data synchronization originally implemented by the trigger cannot be achieved. Because the boss of the Director is not allowed to start the distributed

The SQL statement is as follows:Select distinct cp. name AS cp_name, c. name AS category_name, t. name AS type_name FROM g LEFT JOIN  cp ON cp.id = g.cp_id AND cp.deleted = 0 LEFT JOIN  c ON c.id = g.category_id AND c.deleted = 0 LEFT JOIN  t ON

Comprehensive Sqlite Learning (2) and sqlite Learning Finally, CSDN was chosen to sort out the knowledge points published over the past few years. This article was migrated to CSDN in parallel. Because CSDN also supports the MarkDown syntax, it's

When you remotely connect to mysql, the message "is not allowed to connect to this MySQL server" is displayed. mysqlallowedERROR 1130: Host '192. 168.1.3 'is not allowed to connect to this MySQL server. this tells you that you are not authorized to

PostgreSQL tutorial (10): Performance Improvement tips and postgresql Performance Improvement 1. Use EXPLAIN: PostgreSQL generates a query plan for each query, because selecting the correct query path has a critical impact on performance. PostgreSQL

To perform time operations in SQL, You need to master four time functions: dateadd, datediff, datepart, and datename.Dateadd is to add or subtract a time on a specified date.For example, if you add a 3-day select dateadd (day, 3, '2017-05-06 ') on

15 required MySQL management tools for DBAs and 15 required mysql for DBAs Original article: http://www.techxue.com/techxue-11898-1.html Today, the response speed of Web applications is one of the keys to success. It is closely related to user

In Oracle, table columns are changed from VARCHAR2 to CLOB and varchar2clob.Scenario The columns in the original table are defined as the VARCHAR2 type. As we all know, the maximum length of the VARCHAR2 type is 4000. If you want to convert this

Inconsistent recovery of data file headers and inconsistent recovery of Data Headers SYS@orcl11g>alter database datafile 6 online;alter database datafile 6 online*ERROR at line 1:ORA-01113: file 6 needs media recoveryORA-01110: data file 6:

As one of the mainstream databases in the current market, Oracle databases are developed on many applications. Due to the reasons for upgrading Oracle databases and different application providers, several Oracle versions may exist in an application

Database partitioning is one of the key functions required by each database. Almost all Oracle databases use the Partition Function to improve query performance. The Oracle 11g Partition Function simplifies the daily management and maintenance of