Database Administrator

Create a file named Oracle [root@stark init.d]# pwd  /etc/init.d  [root@stark init.d]# touch oracle  Add the following content to oracle: #!/bin/bash  # chkconfig: 35 95 1 

Take utf8 as an example. Assume that you have installed MySQL in Ubuntu (SEE) and the installation is successful. 1. Stop mysql Sudo/etc/init. d/mysql. server stop 2. modify my. cnf Sudo gedit/etc/my. cnf Find the corresponding part and add the

When multiple instances run on the same server, the concept of instance cage is introduced from Oracle 11gr2 to avoid mutual impact between instances. Instance cages can limit the CPU resources used by database instances. To use an instance cage,

Paste a configuration example using cassandra 1. Configure the jdk1.6 and later environments.Check the java version after installation. It must be java version "1.6.0 _ 24" or later. Otherwise, an error similar to out of memory will be reported

DRCP is the Database Resident Connection Pool. The default Database is sys_default_connection_pool, but it is not opened. Start DRCP:Sqlplus/as sysdbaExecute dbms_connection_pool.start_pool ();It can be executed on any instance in the RAC

In the Oracle database, we can use oracle internal events to adjust the SCN. There are two common methods to improve SCN: 1. alter session set events 'immediate trace name ADJUST_SCN level x ';-- Database OPEN is required 2. Event 10015Alter session

Recently I encountered the problem of "TNS-12535: TNS: Operation timeout. 1. First, check whether the server has enabled the firewall. The firewall blocks connections.Linux Firewall shutdown command: service iptables stop or chkconfig iptables off2.

I. Problem Description Database Error. Read alertlog, which repeats the following content: Wed Jul 25 17:47:18 2012 Errors in file/oracle/admin/etldb/udump/etldb_ora_15674.trc: ORA-07445: exception encountered: core dump [kghssgdmp () + 273] [SIGFPE]

1. view the maximum number of Oracle connectionsSQL> show parameter processes # maximum number of connections 2. Modify the maximum number of connectionsSQL> alter system set processes = value scope = spfile # value indicates the number of

Installing MySQL in Ubuntu saves a lot of trouble. Basically, I sorted out the online materials.1. Install MySQL Sudo apt-get install mysql-server mysql-client # You will be asked to enter the root user password once in the middle   Sudo

The problem is that I want to obtain two adjacent rows with a row of records in a table and want to obtain them through union, so I write: Select id, title from subjects where id> # some_id # order by id limit 1 Union Select id, title from

If you encounter a large amount of AWR data in your daily work, you can clear it as follows:SQL> select distinct dbid, db_name, instance_name from wrm $ _ database_instance;DBID DB_NAME INSTANCE_NAME-----------------------------------2691876695 MYDB

Establish package specifications Create Or ReplacePackage emp_packageIs G_deptno number (3): = 30; ProcedureAdd_employee (eno number, ename varchar2, sal number, dno numberDefaultG_deptno ); ProcedureFire_employee (eno number );

In Oracle 9i/10g, if the database instance does not have the scott mode, you can manually create it as follows: Log on to the database Create scott user Assign permissions to scott users Log On with scott user 1. Execute the following SQL

When creating a 10g Database on the ASM instance of Oracle11.2 RAC, an error is reported: The Cluster Manager cannot be connected, and the ASM instance cannot be located. The error message is as follows:ORA-15077: cocould not locate ASM instance

1. How to log on to the database through operating system authentication 1) The most basic method is to use "sqlplus/as sysdba" to log on to the database. Sqlplus/as sysdba The slash "/" indicates the user name on the left and the password on the

HWM in Oracle) Find a table with a large number of records, for example, test1. Create table test2 as select * from test1 where 1 = 2; Insert into test2 select * from test1; The session is forcibly interrupted before the insert operation is

I am a man-level character in Oracle, so I have encountered many problems. In the last few days, oracle data queries have encountered a strange phenomenon. A database is running on a different computer and in the same environment when pl/SQL is

Requirement: Now you need to change the field name, add a field, delete another field, and change the field type. Create the following table (original table ):Create table month (Id INT,Week VARCHAR (10 ),Day VARCHAR (10 ),Hour VARCHAR (10 ),Primary

Mysql backup and AB ReplicationThere are two replication methods: Synchronous replication (msylq-cluster) asynchronous replication (mysql-m/s master-slave backup is also called dual-machine Hot Backup) I. Mysql full backup (pure copy mode and