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RDBMS Server

Oracle RDBMS Server Articles

How to Identify OS or Oracle 64 bit or 32 bit

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.

Oracle 10g - Manually Create a Physical Standby Database Using Data Guard

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.

Why I Choose Oracle as My Career?

Mohammad taj's picture

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"

How to compile Invalid Object?

Mohammad taj's picture

There are five ways to recompile invalid objects in schema.

5. Manually Recompile



This procedure is equivalent to the following SQL statement:


Exec dbms_ddl.alter_compile ( type , schema, name);
Schema : Database Username

Name : Objects name


Migrating Databases From NON-ASM to ASM

Mohammad taj's picture

Dear Friends,

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;
System altered.
SQL> alter system set db_create_file_dest='+DGRP2' scope=spfile;
System altered.

How To Move The Database To Different Diskgroup Migrating from External Redundancy to Normal Redundancy

Oracle RDBMS Server - Enterprise Edition - Version:
OS: Applies to any OS, But this is tested on AIX5.3L


Moving Data between Disk groups

Table Fragmentation

Mohammad taj's picture

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.

Tuning a 'LIKE-clause' by using Oracle Text or Reverse Key Indexes

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.

Materialized View Fast Refreshes are Slow

vjain's picture

A materialized view that is verified to be fast refresh should update relatively fast. But, what happens when there are few changes to the master table, no network issues, no aggregation in the snapshot query and the refresh still runs slow?

Sizing your undo tablespace

sethunathu's picture

It is always a puzzle for a DBA to look into the user's complaint of getting "ORA-01555 Snapshot too old : rollback segment number x with name "_SYSSMUx$" too small " error. You have looked into the database. If your UNDO_MANAGEMENT is set to AUTO, you can not do anything to size the rollback segments manually since it is being managed by oracle. All the associated tables and indexes have been analyzed and statistics are up to date. The undo tabelspace is almost full. You may advise the user that there should be frequent commits (if it is a data loading process) or if there is a long running query and other users change the data that is being selected by the query, this can happen and in that case, if possible, advise the user not to run these two at the same time.