Database Administrator

The role, benefits, and disadvantages of ASM storage are not described here. There are many documents related to google! This article mainly records how to use the ASM storage in Oracle 11.2.0.3! Related software packages can be found

FunctionParametersBySpecified separatorDelimiter ValueOfSet(For example, 123,12, 55,2222, 90))Function return In the setMaximum Value, MinimumValueIn the collection andIn the setNumber of Values. /* Example: Run the following function Select *

In fact, this problem was previously encountered by the same customer. At that time, an engineer resolved the problem and recorded the process as follows: The application colleagues reported that the stored procedure had been executed for 2 or 3

Environment: MySQL Server 5.1 + Navicat for Mysql 8.2 Problem: A 121 error occurred while deleting the foreign key. Solution: Change the foreign key name to another name. For error information, refer: Error 121This is an error where the names

For work, you need to write a method or SQL statement to retain the decimal point. For decimal places of the number type, if it is 0.5 or-0.5, it will be displayed during printing. 5 or -. 5. Obviously it's not what I want. I wrote a simple one

1./etc/oratab description Use cat to view the file: Gg1:/home/Oracle> cat/etc/oratab # # This file is used by ORACLEutilities. It is created by root. sh # And updated by the Database ConfigurationAssistant when creating # A database. # A

In view of redis list, hash, set, string and other types of operations, many people are familiar with the use of, a brief introduction to dynamic parameter modification, master-slave switchover, persistent settings, system information

Problems with Oracle DG archive setup Verification -- Master database SQL> col statusForA10 SQL> col destinationForA20 SQL> col errorForA20 SQL>SELECTSTATUS, DESTINATION, ERRORFROMV $ ARCHIVE_DEST; STATUS DESTINATION ERROR -----------------

When I was writing JDBC, I met the problem that the SQL statement cannot run because it contains Chinese characters. So I put this sentence in the mysql client for testing and the result passes, I guess it's not a matter of character encoding. It's

I used Ubuntu 10.04 LTS Server. The HDD was faulty a few days ago and the system was pregnant. I had to wait for an 80 GB HDD to be eliminated with IT. How can the company be so poor, I still use my computer as the server 7 or 8 years ago. Is IT

1. Add a user to Mysql Format: grant select on database. * to "username" @ "Login host" identified by "password "; Example 1: Add a user named "test1" with the password "abc" so that the user can log on to any host and have the permission to query,

If you have not installed or used sqlite, you can use SQLite3 for installation and basic operations. 1. Create a database test. db Cd ~ / Sqlite3 test. db In this way ~ /A database file test. db is generated under the directory. 2. Create a table

Function: The purpose of using a function is to operate data. Process the input variable and return a result. There can be many variables. The input variables can be column values or expressions. Functions can be nested. The result of the inner

Create undo tablespace MOZI datafile 'e: \ Oracle \ product \ 10.2.0 \ oradata \ orcl \ MOZI. dbf' size 2048 M extent management local;Alter system set undo_tablespace = MOZI;The ORCL database in WINDOW prompts: the database is not open: it can only

State online can be started only after the dual-node RAC is successfully installed on the VM. you can always have several UNKNOWN machines after each restart, if you can start them manually. crs_start ora. xxxxx, or crs_start-f xxxxx If no error is

1. Command installation: yum install mysql-server 2. built-in startup: CentOS6.2 comes with mysql5.1 installed, and the root identity (mysql-u root-p) has no password; System-> Management-> service, select mysqld, and set auto start and start the

The database initialization parameters used for Oracle Database startup are usually obtained using the show parameter command in sqlplus. However, only some public parameters and modified hidden parameters are shown here. Oracle also has a number of

In the basic configuration information table of the application, some dictionary information is saved. The key value is added by the application in sequence as needed. This type of requirement is used for primary key field value management. The

Db2 instances and databases are installed on shared disks. To use a crontab scheduled task to back up the DB2 database, because it is an HA environment, we need to consider the scripts on the two machines. Edit crontab and set scheduled tasksLog on

Introduction: When processing a sequential account with similar records, you may often encounter the situation of "taking the first and last records for calculation on a certain Table value. For example, the logging and end-to-end increase.