Database Administrator

Oracle Database is one of the most complex databases so far. This complexity allows Oracle databases to meet various requirements of enterprises. However, most of the time, the database administrator has some skills to simplify database maintenance.

After installing Oracle, you want to use other Linux users to log on to sqlplus,$ Usermod-g oinstall zhou$ Cp/home/oracle/. bash_profile/home/zhou/. bash_profile Failed to find!The following problems occur:SQL * Plus: Release 9.2.0.1.0-Production

According to foreign media reports, Trip Chowdhry, an analyst at Global Equities Research, said, oracle may need to strip or sell Sun's MySQL open source database business to obtain approval from the EU Anti-Monopoly Regulatory Authority for Sun's

What is the file structure of the MySQL database? For the Database Command created in this way: Create database mysqldb The default database storage location contains a folder named mysqldb. To operate the database, you must stop the database

The authoritative eWeek test shows that MySQL 4.0.1 is comparable to Oracle 9i. EWEEK Labs/PC Labs can be said to be the leader in Benchmark Testing. As early as October 1993, their sister Magazine PC Magazine did the same test. This cooperation

Today, the company purchased a us vps, Linux operating system, which is managed through the Container. The system is pre-installed with MYSQL, And the password is generated randomly (contact the technician over there to obtain satisfactory results)

Recently, I encountered a server that used Oracle databases. After learning Oracle + for advice, I finally got all the user passwords on the website background management interface. I found it too troublesome to operate Oracle, in order to avoid

Ubuntu Navicat for MySQL installation: 1. Navicat for MySQL official download 2. decompress the tar file after the download.Tar-zxvf navicat8_mysql_en.tar.gz 3. decompress the package and run it in the decompressed directory. ./Start_navicat

Create or replace view V_WTK_ALL Select a. id, o. short as FindDeptName, u. realname as FindUserName, f. name as FindWay, o1.short as ProblemAtDeptName, Z. name as szzz,. yhnr, s. name as SSZY, k. name as kind, w. name as whhg,. zgcs,. zgfzr,.

A strange problem occurred when importing a data from an Oracle database. Chinese characters are garbled. First, you can confirm that the data in the database exists in Chinese, and that the data is also in Chinese when you use Toad for connection

1. Exceptions. When Hibernate is used as the project persistence layer, an extension is required for a table. The extension operation is to create a trigger for the table. Read data from a table into other tables. The SQL statement is as

Install MySQL-server-5.6.13-1.el6.x86_64.rpm under RedHat 6.3 First, download the following three files: MySQL-client-5.6.13-1.el6.x86_64.rpmMySQL-devel-5.6.13-1.el6.x86_64.rpmMySQL-server-5.6.13-1.el6.x86_64.rpm Then use the root account to log in

RMAN is a backup recovery tool provided by Oracle. In fact, using SQL combined with OS commands can also execute Backup recovery, which is more flexible, but it is better for beginners to use rman; Rman manages backup, dumping, and recovery

ORA-16139: media recovery required error encountered during physical DG Master/Slave database switchover SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY; ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY * ERROR at line 1: ORA-16139: media

There are two main causes:1. There is a large volume of transactions that allow Oracle Undo to automatically expand, resulting in excessive disk space occupation;2. There are large transactions that have not been contracted or are not committed by

1. Enable event tracking 10046Alter session set events '2017 trace name context forever, level 12 '; 2. Execute an SQL statement at Will (we will find the execution of this SQL statement in the trace file)Select * from dba_users where username = 'hr

OS: CentOSDB: PostgreSQL9.3, OS user: postgres I. Compile the pg_dump backup script: # get the day of week 1-7 starting mon=1DOW=`date +"%u"`# define variablesDB_INSTALL_DIR='/opt/PostgreSQL/9.3'# DB_TYPE='PostgreSQL'# DB_SERVER='127.0.0.1'# DB_PORT=

The default naming conventions for this file are:Init $ Oracle_SID.ora (in Unix environment)Init % ORACLE_SID %. ora (in Windows) By default, it is placed in the following directory$ ORACLE_HOME/dbs (Unix)% ORACLE_HOME %/DATABASE (Windows)This

For an Oracle database user, a table must be read/write controlled and can only be read and written, but cannot be deleted or modified. Developers start to want to implement it with user permissions. After some discussion, it is inappropriate to

If you delete a non-existing TABLE in Oracle, such as "drop table notExistTable", the following message is displayed: ORA-00942: Table or view does not exist, If you run this statement using a program, an exception is reported. You need to delete