Database Administrator

1. mysqladmin-uroot-poldpassword password newpassword2. mysql> update mysql. user set password = PASSWORD ('new password') where User = 'root ';Mysql> flush privileges;Mysql> quit3. mysql-u root mysqlMysql> UPDATE user SET password = PASSWORD ("new

1. Create a space for the db Data File Mkdir-p/db2root/testdb/lv_db2dbMkdir-p/db2root/testdb/lv_db2indexMkdir-p/db2root/testdb/lv_db2logMkdir-p/db2root/testdb/lv_1_bsMkdir-p/db2root/testdb/lv_temptbsTouch/db2root/testdb/lv_usertbsChown-R db2inst1:

If you are using Oracle 8i or a later version, it is simple. execute immediate SQL _str is used in the process. SQL _str is a patchwork SQL statement, but this dynamic statement contains parameters, or when the Select result is into the variable,

Oracle databases are typical representatives of network databases. You can access the Oracle database over the network. Oracle Database provides a variety of network interconnection solutions, including the structure and driver, its network

Directory Preface Chapter 1 hardware preparation Chapter 2 software preparation Chapter III installation in 11.5.10 For Linux Chapter 4 Maintenance and problem solving after installation Chapter 5 release of ebs Oracle EBS 11.5.10 Study Notes

Run Oracle database EM, isqlplus, and other commands in Linux. $ ORACLE_HOME/bin/emctl start dbconsole $ ORACLE_HOME/bin/isqlplusctl start Common emctl command syntax: Emctl start dbconsole to start the EM console service. You need to set the

When Oracle11g is installed on RedHat as5, the GUI cannot be started and the following error is reported:[Oracle @ sense disk1] $./runInstallerStarting Oracle Universal Installer...Checking Temp space: must be greater than 80 MB. Actual 1184 MB

1. Check whether the system information meets the Oracle installation requirements.Df-k | grep tmp # & gt; 521 MMore/proc/meminfo | grep MemTotal # & gt; 512 MBMore/proc/swaps #> 1024 MBMore/proc/sys/kernel/sem #> = 250 32000 100

Performance optimization is a big topic, ranging from program architecture optimization to database design to a specific algorithm or js optimization. Here we will only briefly discuss the performance optimization of hibernate. When using Hibernate,

MySQL 5.6 master-slave replication Part 4 [some ignored Operation Details] 1. STOP SLAVE There are two types of threads responsible for synchronization from the server:1) IO thread2) SQL thread IO thread is responsible for obtaining binary logs on

ASM is a storage product released by Oracle for rac. Although it is set for the cluster environment, we can also use ASM instances to manage disks in a single-host environment. (1) installation and configuration I. Confirm the Linux kernel

Connection character: |Value assignment: ": ="For example, l_name: = 'sky ';Determine whether the values are equal: "="For example, if 1 = 1 then...Variable binding :":"For example, if: P_NAME = 'sky' then... ExistsNot exists does not exist % Type

In SQL query statements, many people often doubt the query efficiency of in and exists. Many people think that the query speed of exists is faster than that of in. in fact, this statement is not absolute, both exists and in have their appropriate

1. What is the Oracle character set? The Oracle character set is a collection of symbols for the interpretation of byte data. It can be divided into different sizes and have an inclusive relationship. ORACLE supports the national language

After the environment is set up, enter the command proc in the terminal If the following error message is displayed: [Oracle @ oracleserver ~] $ ProcProc: error while loading shared libraries: libclntsh. so.10.1: cannot open shared object file: No

Oracle queries the usage of temporary tablespace: Select d. TABLESPACE_NAME, SPACE "SUM_SPACE (M)", BLOCKS SUM_BLOCKS, USED_SPACE "USED_SPACE (M)", ROUND (NVL (USED_SPACE, 0)/SPACE * 100,2) "USED_RATE (% )", NVL (FREE_SPACE, 0) "FREE_SPACE (M

1. Compare the size function SIGN Sign (x) or Sign (x) is called a symbol function. Its function is to take a certain number of symbols (positive or negative ):When x> 0, sign (x) = 1;When x = 0, sign (x) = 0;When x X can be a function or computing

Because there are not many flash areas, select * from v $ flash_recovery_area_usage and find that the backup set occupies too much space.So delete obsolete; found the error ORA-19606: Cannot copy or restore to snapshot control file RMAN> delete

Description of the new and enhanced RMAN functions in Oracle Database 11g• Configure an archiving log deletion policy • Use the Oracle network to copy active databases (No backups) • backing up large files in multiple parts • Creating archive

Key points about setting a reasonable log buffer size 1, default size MAX (0.5 M, (128 K * number of cpus )) 2, On most systems, sizing the log buffer larger than 1 M does not provide any Performance benefit. It merely uses extra memory. 3. View