Database Administrator

This article demonstrates how to use Oracle ROLLUP grouping functions to experience the charm of Oracle functions in the field of statistical query. The ROLLUP grouping function can be understood as the simplified usage after the Group By grouping

Starting from Oracle10g, sqlplus provides a parameter option-prelim, which is used when the system has hang. We can connect to SGA instead of the database, that is, no session is created. 1. Follow these steps to obtain system

Oracle software version: 10.2.0.5 Oracle Installation Directory:/u01 Copy the entire Oracle directory from the source server to the target server in lync mode. It is reasonable to say that software migration will not cause serious errors. However,

1. Oracle client Configuration 1. find the oracle installation directory → db_1 → NETWORK → ADMIN → modify the listener. ora file and tnsnames. open ora notepad and check whether the host is the host name of the current computer. If not, change it

Prerequisites for Database Import and Export: 1. Install the Oraclek client or server locally. 2. connect to the target database through the NetConfiguration Assistant provided by oracle. The first step is needless to say. The second step is to open

/Etc/my. cnf Configuration [Mysqld]Datadir =/var/lib/mysqlSocket =/var/lib/mysql. sockUser = mysql# Default to using old password format for compatibility with mysql 3.x# Clients (those using the mysqlclient10 compatibility package ).Old_passwords =

Environment: OS: Red Hat Linux As 5DB: 11.2.0.1 11G has greatly improved the volume uard, the slave database can still apply the archive logs uploaded from the master database. Remember to open the slave database to check whether the data has been

1. Reduce the control file. If a control file is corrupted, we need to remove the corrupt control file. Steps:1. Modify the parameter file and verify2. Stop the database3. Start the database4. Verify and view v $ controlfile The following is the

View the value of the environment variable used by an Oracle process. When nls_lang is null, we want to know the default value. When installing the version, we want to know that a process is generated by the database of that version, we can use the

1. Fault Cause Use ruby to permanently delete all tables under the ql user, and the recycle bin does not exist. Therefore, the use of "flashback table" is invalid; Flashback database is disabled; Only recovery through media is supported. 2. Use RMAN

System not only has the permissions of the DBA role, but also has other permissions. Use sys userAuthorizeThe related permissions are found in the dba_role_privs table.Select t. GRANTED_ROLE FROM DBA_ROLE_PRIVS t where t. GRANTEE = 'system ';There

In Oracle databases, the three major files (Data File, Control File, and Online Redo Log) play an extremely important role. The Redo Log and Oracle Redo Log mechanisms guarantee normal and safe operation of Oracle. Oracle Online Redo Log adopts the

According to the official Oracle documentation, the database character set cannot be changed after it is created. Therefore, it is important to consider which character set to use at the beginning of design and installation. For the database server,

MySQL remote Incremental Backup: #! /Bin/sh    # MySQL Info Sqluser = root Sqlpsw = root /Usr/bin/mysqladmin-u $ sqluser-p $ sqlpsw flush-logs --Default-Character-set = GBK DATADIR =/data/mysql BAKDIR =/home/backup/mysql/daily TEMPDIR =

After LNMP is set up, use PhpMyAdmin to import the database file, prompting that the file content is too large. Modified Upload_max_filesize = 30 M Post_max_size = 40 M Still useless. You can solve the problem as follows: Modify the config. inc.

1. Modify the/etc/oratab FileDb1:/home/Oracle/product/11.2.0/db_1: Y$ ORACLE_SID: $ ORACLE_HOME: Y2. Modify the Startup File $ ORACLE_HOME/bin/dbstart.Change ORACLE_HOME_LISTNER = $1 to ORACLE_HOME_LISTNER =/home/oracle/product/11.2.0/db_1.3. Modify

My system: Red Hat Enterprise Linux Server 6.0.My Oracle: 10g. 2.1 Installation Process in silent mode:1) confirm the disk size: u01 5G; swap 400 m;Du-sh/tmp/Df-h 2) install related dependency packages (query the official installation guide

Explore TRIM FunctionsThe simplest function of Oracle TRIM is to use it to remove spaces at the beginning and end of a string row. This function is also the most frequently used function.However, the Oracle TRIM function is actually capable of

An error occurred while connecting to the database using rman today.[Bkjia @ rhel55 ~] $ Rman target sys/Oracle @ orcl ORA-12514: TNS: listener does not currently know of service requested in connect descriptor[Bkjia @ rhel55 ~] $ Lsnrctl

(1) After the Oracle Database Console is started, 1) The database instance has no information. 2) The Listener is in the unavailable state. 3) the proxy connection status to the instance is unavailable. Problem analysis: the service has just started