Database Administrator

1,SYSTEMTablespace data file loss recovery Note: All the following experiments are based on the full-Database Backup above. 3.1DeleteSystemAll data files in the tablespace. [Oracle @ wwldb WWL] $ rm-rf RJE * [Oracle @ wwldb WWL] $ exit   3.2An error

If you want to install the sample user in Oracle11gR2, you can use the example provided in the oracle official documentation. You can create an instance at the same time. You can also create a database after installing the database software database.

Oracle 11gR2 is installed in Oracle Linux 6.0 (also suitable for other linux versions of RedHat ).There is no major difference in the installation under. After all, the three linux releases are more different in log.This document is a review after I

1. Requisitions Path: Purchasing> Requisitions There are only two types of requisitions. One is Internal Requisition, which is used for material application between Internal organizations; the other is Purchase Requisition, which is used to

Build Environment: Red Hat Linux Enterprise 5.4 Oracle 10g R2 The host operating system information is 192.168.199.128. Preparation: The master database (production database) DB_NAME = mustang SID = l already exists. Start building Data Guard First,

SQL Server Cpu 100% is not very common. It generally causes performance problems, such as blocking, connections, and I/O disks. Therefore, the usage of SQL Server is generally low. However, in some cases, the Cpu usage is 100%. What operations does

SQL> conn hr /***SQL> select username, sid, serial #, module, action from v $ session; Select username, sid, serial #, module, action from v $ session ORA-00942: Table or view does not exist Solution: Sqlplus "sys/*** as sysdba"SQL> grant select on

By default, mysql compilation and installation may fail to connect to mysq server after installation, and an error is reported. "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysql. sock' (2 )" This will cause a

Experiment document: Process: Create a table-backup-simulate downtime (delete a table)-restore a backup-restore the current data.1. Restore and restore the experiment Create a database and use the drop statement to simulate database downtime. Use

1Create original table and Data SQL> create table t1 (id number, name varchar2 (20 )); Table created SQL> insert into t1 values (1, 'A '); 1 row inserted SQL> insert into t1 values (1, 'B '); 1 row inserted SQL> insert into t1 values (2, 'C '); 1

How to automatically start Oracle over 10 Gb instance databases when Linux is started: # Description: start or stop oracle./Etc/rc. d/init. d/functions# Oracle_envExport ORACLE_BASE =/u01/app/oracle/db10gExport ORACLE_HOME = $

1. After some environment variables are configured during Oracle Installation, restart and log on to localhost login: InterfaceCause:======================================# Vi/etc/pam. d/loginAdd the following content at the end of the fileSession

Merge data using relational algebra1Relational algebraThe theoretical basis of Data Set merging is relational algebra, which was proposed by E. F. Codd in 1970.In the formal language of relational algebra:Tables or data sets are used to represent

The first three paradigm of database design is that the independent table structure must have a unique primary key to identify the table data.SQL Server (duoOn the platform. Manually encode the primary key in the table and set it as an

1. Log On As an Oracle user 2. Compile an automatic backup script and clear the archived logs. $ Vi/home/oracle/backs. sh #! /Bin/shSource/home/oracle/. bash_profileCd $ ORACLE_HOME/binRman target/nocatalog msglog =/home/oracle/rman_bk _ 'date' + %

If the database contains a federated primary key, such as Vcode and Vcompany (view method, right-click the Oracle database table and then view the key information to find the UK Information) Verify whether the Vcode and Vcompany are associated

Common index-related scanning methods are as follows:Index range scan ):1. for unique index, if the where condition is followed by ,... and... if the where condition is followed by =, then index unique scan may be executed.2. For none unique index,

We check whether the ASM disk space passes through the following routine: Export Oracle_SID = + ASM1 By checking the v $ asm_diskgoup view, you can check the usage of the disk space as follows:SQL> select group_number, name, total_mb, free_mb from v

Oracle Special Character Processing search and replacement A colleague encountered a special character matching Replacement problem a few days ago. Here is a summary. What should we do if our data contains special characters such as line breaks and

1. Redis storage mechanism Redis storage mechanisms are divided into two types: Snapshot and AOF. Regardless of the Mechanism, Redis stores data in the memory. How Snapshot works: It stores data in the memory first, and then triggers a DUMP