I've been working on way to capture changed rows using ora_rowscn for part of an ETL routine. Here are some details of what I've tested and found.
By default, the ora_rowscn pseudo column reports the scn at block level. This means that rows sharing the same block will have the same ora_rowscn, and if one row were to be changed, then scn would be altered for both blocks.
Once the standby database is setup using Data Guard and works properly, you may want to test switchover, or perform switchover to reduce primary database downtime during OS upgrades or hardware upgrades. (To set up a Physical Standby database, please refer to my OraFAQ blog “Oracle 10g – Manually Create a Physical Standby Database Using Data Guard”.)
A switchover allows the primary database to switch roles with its standby database. There is no data loss during a switchover.
How to Identify OS or Oracle 64 bit or 32 bit on Unix
It is very common question which version of oracle I need to install. 32 bit or 64 bit? As a 64-bit operating system can support either a 32-bit database or a 64-bit database. A 32-bit operating system cannot support a 64-bit database. So, version identification of the OS is necessary prior to install oracle.
Step-by-step instructions on how to create a Physical Standby Database on Windows and UNIX servers, and maintenance tips on the databases in a Data Guard Environment.
Oracle 10g Data Guard is a great tool to ensure high availability, data protection and disaster recovery for enterprise data. I have been working on Data Guard/Standby databases using both Grid control and SQL command line for a couple of years, and my latest experience with Data Guard was manually creating a Physical Standby Database for a Laboratory Information Management System (LIMS) half a year ago.
There are some question which asked frequently on forums from every oracle newbie.
1. Which Oracle Certification I choose ?
Here I will explain in details.
There types of Oracle Certification we can do.
1. Oracle DBA
2. Oracle Developer
3. Oracle Application DBA
1. Oracle DBA
The person which maintain Oracle Database called Oracle Database Administrator.
There are some frequent work for Oracle DBA
1. Database Backup Responsibity.
2. Database Performance Tunning
3. Database Basic Administration Like " user creation, database security"
There are five ways to recompile invalid objects in schema.
5. Manually Recompile
This procedure is equivalent to the following SQL statement:
ALTER PROCEDUREFUNCTIONPACKAGE [.] COMPILE [BODY]
Exec dbms_ddl.alter_compile ( type , schema, name);
Type : Must be either PROCEDURE, FUNCTION, PACKAGE, PACKAGE BODY or TRIGGER.
Schema : Database Username
Name : Objects name
In this article we focus on How to migrate existing database to ASM.
Login to SYSDBA user and alter below three parameter for controlfile,datafile or FRA location with SPFILE option.
1. First need to set below parameter for controlfile,datafile or FRA.
NOTE: I have two disk group here I am using "DGRP2" disk group.
SQL> alter system set control_files='+DGRP2' scope=spfile;
SQL> alter system set db_create_file_dest='+DGRP2' scope=spfile;
How To Move The Database To Different Diskgroup Migrating from External Redundancy to Normal RedundancySubmitted by reddy_uk on Mon, 2007-12-03 14:09
Oracle RDBMS Server - Enterprise Edition - Version: 10.2.0.2
OS: Applies to any OS, But this is tested on AIX5.3L
Moving Data between Disk groups
When rows are not stored contiguously, or if rows are split onto more than one block, performance decreases because these rows require additional block accesses.
Note that table fragmentation is different from file fragmentation. When a lot of DML operations are applied on a table, the table will become fragmented because DML does not release free space from the table below the HWM.
The LIKE-clause can ignore indexes, causing queries to run forever while doing full table scans. This document describes how to tune such SQL statements by making use of Oracle Text or reverse key indexes.