Database Administrator

Modify the corresponding Kernel Parameters Kernel. sem = 250 32000 100 128Kernel. shmmax = 2147483648Kernel. shmall = 4194304Kernel. sem = 250 32000 100 128Net. ipv4.tcp _ rmem = 4096 4194304 4194304Net. ipv4.tcp _ wmem = 98304 4194304 4194304Net.

Backup files can be customized in the following formats: % C Number of copies of backup slices % D Database Name % D the day in the month (DD) % M is in the month of the year (MM) % F a unique name based on DBID, in the form of a

Oracle entry commandBasic commands:1. the spool command is used to screen recording in sqlplus.Spool c: \ 1.txt automatically creates 1.txt, screen recordingSpool c: \ 1.txt appendAdd to 1.txt2. conn system/orcl switch user connection3. -- meaning

This operation is not difficult because data correction is often required during work. Rollback is required during operation ~ For rollback requirements, I usually perform a backup table and then perform a change! If a correction error is sent or

Why Oracle cursor: First look at this: DECLARE V_empno emp. empno % type; V_ename emp. ename % type; BEGIN SELECT empno, ename Into v_ename, v_empno FROM emp; Dbms_output.put_line (v_empno | ''| v_ename ); END; This SELECT

First install the monodevelop and mono development environments as described Install mongoDB on linux according to the official mongoDB example: http://www.mongodb.org/display/DOCS/Quickstart+Unix,Note: Download different versions based on whether

// There are mainly the following two system tables. pg_largeobject_metadata records the permissions mainly. Only pg_largeobject is useful. CATALOG (FIG, 2995) { Oid lomowner;/* OID of the largeobject owner */ # Ifdef CATALOG_VARLEN/*

In Linux, mysql is often used to connect to the server every time: [Root @ localhost ~] # Mysql-hlocalhost-uroot-p11111 Every time I enter the user name, password, and more people, is there a more convenient way? We only need to simply configure

I. Overview:A database can be considered as a name set of an SQL object (database object). Generally, each database object (table, function, etc.) belongs to only one database. However, for some system tables, such as pg_database, it belongs to the

Introduction to Oralce Character Set Oracle character set is a common problem. Set the character set of window: regedit-> HKEY_LOCAL_MACHINE-> SOFTWARE-> ORACLE-> HOMEO-> NLS_LANGWindows: SIMPLIFIEDAMERICAN_AMERICA.ZHS16GBK View character set in DOS:

An error occurred after Oracle 10201 was upgraded to 10204. SQL> startup ERROR at line 1:ORA-01092: ORACLE instance terminated. Disconnection forced Alert Errors in file/oracle/admin/mydb2/udump/mydb2_ora_5811.trc:ORA-00704: bootstrap process

Uninstall MySQL in Ubuntu 12.04 Step 1 1 sudo apt-get autoremove -- purge mysql-server-5.0 2 sudo apt-get remove mysql-server 3 sudo apt-get autoremove mysql-server 4 sudo apt-get remove mysql-common (very important) Step 2: Clear residual

View Current Character Set ReferenceSQL> select * from nls_database_parameters where parameter like '% SET % '; PARAMETER VALUE----------------------------------------------------------------------NLS_CHARACTERSET WE8ISO8859P1NLS_NCHAR_CHARACTERSET

I. Applicable background There is a database named test, whose data is in the device test, and the log is in the device test_log; The test database has a table tab1 with 5 Records (1-5 ); Complete database backup: dump database test to

Since Oracle 10 Gb has not yet come out of the red-flag Linux Asianux 3.0, it is better to install the rpm package according to the requirements of Asianux 2.0. We must have the following RPMs installed:Red Hat Enterprise Linux 4.0 and Asianux

Since Oracle version 10g, data Pump is provided as a new data mobile technology. The technical tools are expdp and impdp respectively. We often use them in actual projects, such as migrating data from the production database to the test database. I

The database version installed on my local machine is Oracle 11G R2. When I connect to the database today, the following error is reported: Oracle not available ORA-01034 ORA-27101-shared memory realm does not exist I found several solutions online,

This experiment uses the duplicate command to create a copy database in the local environment. The target database is hongye, And the copied database is catdb. Environment alias settings:Alias SQL = 'maid sqlplus/nolog'Alias rman = 'rlwrap

We know that every RDBMS has its own characteristics in SQL. So today, let's take a look at the characteristics of Oracle, which deserves our attention. Feature 1:Oracle analysis functions and window functions:Syntax: FUNCTION_NAME (, ...)OVER (

Oracle Network Configuration Three configuration filesListener. ora,Sqlnet. ora,Tnsnames. oraAll are placed in$ ORACLE_HOME \ network \ adminDirectory.1. sqlnet. ora ----- SimilarLinuxOr otherUnixOfNsswitch. confFile to determine how to find a