Oracle

There are four common principles in transactions that all databases must adhere to, the acid principle, and a brief overview of how Oracle achieves these four principles. I. atomicity (atomicity): A transaction is either all executed or none of the

1, CHAR.Char is convenient to store the fixed-length data, the index on the Char field is more efficient, such as the definition of char (10), then regardless of whether you store data reached 10 bytes, to take up 10 bytes of space, insufficient to

1. Nls_lang parameter compositionThe Nls_lang parameter consists of the following parts:Nls_lang=_.Nls_lang the meanings of each part are as follows:LANGUAGE specifies:-oracle the language used for messages-Date month and day displayTerritory

Ora-01548:active rollback segment ' _syssmu1$ ' found in Oracle"Oracle Undo tablespace Recovery (no backup)" above http://www.linuxidc.com/Linux/2014-06/103779.htmUndo Table Space Loss for Rman backup and recovery http://www.linuxidc.com/Linux/2014

Oracle database 10g introduces the latest data Dump technology, enabling DBAs or developers to quickly move database metadata (object definitions) and data to another Oracle database.The role of Data Pump export import (EXPDP and IMPDP)1. Implement

Because Oracle sets the primary key is not automatically incremented, you must use sequences and triggers to complete the increment of the primary key1. Set up a data sheetCREATE TABLE Test_increase (UserID Number (primary key,/* Establish PRIMARY

Serial number Function description Shortcut keys Note 1 Hide Query Results F2 2 View Object Details F4 3 Clear Screen F7 4 To

Using Oracle's Sql*net v.2 to connect clients and servers, you need to configure each client and server.     The files that need to be configured on the server are: Listener.ora,/etc/services, and the Tnsnames.ora file needs to be configured on the

This article has looked for an Oracle architecture diagram from the Internet for an overall description of Oracle 's Architecture 1 oracle database mainly has data files Database instance composition. Users are linked to server process

This section describes the various index scanning methods, and after understanding the characteristics of the various index scanning methods, you can determine whether the scanning method used in your execution plan is correct, and can make

A problem occurred in the previous period, that is, restarting a RAC node suddenly reported that the recovery area is insufficient, check that there should be no problem, has been modified to 500G, there should be more than 200 g of the remaining

Common commands for Sql*plusConnection command1.conn[ect]USAGE: Conn username/password @ NETWORK SERVICE name [as Sysdba/sysoper] when connecting with a privileged user, you must bring as SYSDBA or as Sysoper2.disc[onnect]Description: This command

There are two ways to connect Oracle using Sqlplus.First, the Simple waySqlplus username/password @ip or hostname: Port/Database service NameSecond, the way of pre-configuration TNSNamesUnder the "%oracle_home%\network\admin" path, there is a

Oracle goldengate Learning-basic concepts and configurations (2)One, Oracle ogg download:Http://www.oracle.com/technetwork/cn/middleware/goldengate/downloads/index.html650) this.width=650; "src="

1. Cursor ConceptsWhen you execute a SELECT, INSERT, delete, and UPDATE statement in a PL/SQL block, Oracle assigns it a context area, or buffer, in memory. A cursor is a pointer to the area, or a structured data type. It provides a method for

In Oracle, if the foreign key is not indexed, the modification to the parent table causes the child table to be added to the full table lock. This consists of two cases: 1. Delete rows from the parent table, if there is no index on the foreign key,

A plain statement select * from T1, t2 where t1.id = t2.id and t1.name = ' a '; Under what circumstances is this statement most efficient?Table Connection Categories:1. Nested loops connection (Nested loop join)2. Sort Merge Connection (merge sort

Oracle-PLSQL Stored Procedure cursor when output parameter Baotou: Create or replace package ProdureceCursorData isType curtype is ref cursor; Type type_record is record ( Deptno NUMBER (2 ), Dname VARCHAR2 (14 ), Loc VARCHAR2 (13) ); PROCEDURE

Summary of common oracle commands Here, I would like to summarize some common oracle commands that are often used at work, but sometimes they are always forgotten and hope to be useful. The command is as follows: Cmd or sqlplus connect to

Create a composite partition using a template in Oracle11g Using a template to create a composite partition greatly reduces the complexity of the script. Here is an experiment: -- Create a composite partition using the template method SQL> drop