Database Administrator

1. installation: Create bea group and weblogic usersUse root to log on to the operating system and run the following command to create the bea group and weblogic users. Bea group number is 600, weblogic user number is 600, belongs to the bea group,

I. Check hardwareView memory and swapSpaceAnd disk SIZE command: # grep MemTotal/proc/meminfo" # Grep SwapTotal/proc/meminfo2 G']. Q8 O (A # E# Df-h8 l! B % k s 'd; c6 R# Df-k/tmp8 A; k5 f. k j (q % q8 TRequirement: The minimum memory required is 256

The username and password for installing mysql under Ubuntu are correct, but an error is returned when you connect to the database under myeclipse! Specific error code: Access denied for user 'root' @ 'localhost' (using password: YES )! I searched

This problem occurs during programming in C. Generally, the time format is incorrect. The time format generally uses a STRING object when saving variables, However, when you use an SQL statement to input a database, you need to convert the STRING

Due to a problem with the stability of Fedora 14 in my current version, I decided to change it to Ubuntu 10.10, just because I had used this version for a while and felt that it was superior in performance, stability is also good (for the linux

An instance corresponds to an SGA, which can occupy 80% of the physical memory.Shared poolDatabase buffer cacheRedo log bufferOther structures Run the show sga command to view the SGA SGA basic unit: granules (10 M. 16 M) Select componet, If one

Recovery from different machines based on one full backup of rman I. Preparations for the Target database: Back up db Run { Allocate channel specified device type disk maxpiecesize = 10g; SQL 'alter system archive log current '; Change archivelog

Install MySQL 5.5.10 for LinuxOperating System: CentOS 5.5MySQL: 5.5.10 Use the yum Command provided by CentOS Linux to install and upgrade the required libraries (RedHat and other Linux distributions can find the RPM packages of these libraries

1. open_links meaning OPEN_LINKS_PER_INSTANCE specifies the maximum number of migratable open connections globally for each database instance. XA transactions use migratable open connections so that the connections are cached after a transaction is

To achieve maximum performance, databases generally have a concurrency mechanism, but the problem is Data Access conflicts. To solve this problem, most databases Use Data Locking. There are two methods to lock data: Pessimistic lock and optimistic

// % Type// If the declared variable is directly mapped to a column in the database, you can use the % type keyword to map the variable// Pin the column. What are the benefits of doing so?// For example:// Declare v_ename scott. emp. ename % type;//

Sometimes we need to modify the sid and dbname of the database. In addition to using rman for backup and recovery, we can also manually modify it, mainly through two main processes:1. Modify the Instance name (SID)2. Modify the Database Name (dbname)

Each MySQL database directory contains a file db. opt, which is mainly used to store the default Character Set and character verification rules of the current database. Eg. default-character-set = latin1Default-collation = latin1_swedish_ci This

The default "wait_timeout" of the MySQL server is 8 hours (that is, the default value is 28800 seconds). That is to say, if a connection is idle for more than 8 hours, MySQL will automatically disconnect the connection, in general, a connection is

Run the following command to install MySQL in Fedora:Yum install mysql-server Then we create a system startup connection for MySQL (in this case, MySQL will be automatically started when the system starts) and start the MySQL server: Chkconfig --

Insert a data entry in Oracle and return the id of the data entry: /*Create or replace procedure worktask_content_Insert(Theme varchar2,Type varchar2,Status varchar2,Source varchar2,Content varchar2,Slave varchar2,Progress

A few times ago, Oracle Clusterware 10.2.0.1 was installed on RHEL5 or oel5. the main reason was that RHEL5 was not released when Oracle RAC 10.2.0.1 was released, and RedHat was RHEL4, the same problem occurs in SUSE Linux SLES10. The problem

I used SQL Server databases all the time. Recently, my company has a new project to use mysql databases, many of which are cross-Server access. SQL Server uses linked servers for cross-Server access, while mysql is implemented through the Federated

Oracle physical structure faults refer to various database faults caused by damage to each physical file of the database. These faults may be caused by hardware faults or human error. Therefore, we must first determine the cause of the problem. If

A few days ago, the only annual event in the Chinese Database field was held in Beijing at the 2011 database technology conference hosted by Shengtuo media's IT168 website, ITPUB, IXPUB, and ChinaUnix China's three major enterprise-level technical