Wednesday, August 27, 2008

The books, guides, and materials used for my OCA/OCP/OCE Exam Preparation.

Dear All,

As I’m an Oracle Certified Professional on multiple tracks i.e. Oracle Database 10g/9i/8i, Oracle Database 10g RAC Expert Certified, and Oracle 11i E-Business Suite (Application) DBA. So, I have been asked many times in the OTN Forums and by the emails from my blog viewers that "How do you prepare for the certification exams?" And "what advice/tips/suggestions do you have for the certification candidates?"

Even if I have answered to those questions many times, this time, I wanted to have my advice/tips/suggestions posted in my blog for the certification candidates.

01) In addition to any available book in the market for OCA/OCP preparation, I would strongly advice and suggest using Oracle Student Guides/Oracle ILT Materials for your OCA/OCP preparation.

02) Most of the theoretical and logical questions in the real exam are asked from these guides/materials concepts or chapters.

03) These student guides are more simplified and very easy to understand, and have very précised and handy information.

04) The information or concepts of Oracle Student Guides/Oracle ILT Materials have been abstracted, prepared, and developed using the bunch of Oracle Documentations.

05) For writing Oracle Certification Exams, it's very hard to prepare the whole repository of Oracle Documentations. That's why; Oracle University prepared the précised and concise Student Guides/ITL Materials.

06) After finishing thoroughly reading these guides, as many times as you can, till you get the concepts from this materials, the next step is preparing the practice exams, before you take up the real exam.

07) In my opinion and my experience in writing OCP Exams, the practice exams of Self Test Software and Transcender are highly recommended for preparing the OCA/OCP/OCE Exams.

08) This will give you the similar look and feel, and the pattern of the real exam, and helps you manage in real exam.

09) All most of all the practice questions from these test engines (Self Test Software and Transcender) are developed and derived from Oracle Student Guides/Oracle ILT Materials Concepts.

10) Never mug up the practice exam questions and answers, instead try understanding the question and the answer, if needed for any syntax or command sort of questions, do the paper work i.e write the question, syntax or command, and answers in the paper to remember and understand.

11) Concisely what I would suggest is, read the Oracle Student Guides/ILT Materials meticulously as much as you can and do more practice the questions of the test engines (Self Test Software and Transcender) for your Oracle Certification Exam Preparation.

What are the Student Guides/ILT (Instructor Led Training) Materials?
Click here to know about the Student Guides/ILT (Instructor Led Training) Materials

What are the Self Test Software and Transcended Test engines?
Self Test Software and Transcended

For any suggestions, tips, experience of Others on OCA/OCP/OCE, please take a look in the below blog URL.

And also search in OTN Forums for more questions and answers on Certification doubts/questions.
Oracle Certification Forum

One stop for all your Oracle Certification Program Details.
Oracle Certification Program

Oracle Certifiction Program Candidate Guide

OCP 10g Candidate Guide

Oracle Magazine Inside OCP Columns

List of Topics on OCP Exams

Oracle Certification Preparation (OCP)/Hidden Treasures

OCP Hidden Treasures!!!

How important is to an Oracle Certification?

Happy reading !! and best of luck for your Certification Exams !!

Any comments or suggestions are always welcomed.

Sabdar Syed,

How to perform a full database export using original export/import utility?


In my blog, there is a post already available on how to perform a full database export using the new and enhanced feature of Oracle Database 10g Export Utility, Data Pump – expdp/impdp. However, I’m still being requested, by my blog viewers and OTN forum users, to place a procedure on how to perform a full database export using traditional export utility – exp/imp. However, this is not the complete informative post for export/import utility; so, please refer the Oracle Documents links specified at the end of this post.

Before starting off with the steps, to perform the export at the database level, let’s have clear understanding on the following questions.

Can I perform or consider the export of my database as a backup approach?

Absolutely *NO*, because, the import can be done only up to the time the export was originally taken, i.e. the export dump cant be used to import until the point in time (up-to-date) and will not be imported the updates after the export done. This is not acceptable for Production Databases. So, never treat that, taking the export of the database is part of backup strategy of your Production database. In fact, a couple of other approaches are available to perform the backup of your database using the following ways – Cold Backup (Shutdown/Copy/Startup), Hot Backup (ALETER TABLESPACE ….BEGIN/END BACKUP), and RMAN backup methods.

Situations: When and why to perform a full database export.

* Export/import is only the possible way to construct a similar database on remote servers regardless of Operating System compatibility i.e. cross platform (Export on Linux and Import on Windows Systems).
* To migrate the database from one Operating System to another i.e. (Linux/Unix to Windows), and to upgrade the database from one version to another i.e. 8i-9i or 9i-10g, but not vice versa.
* If you are on Oracle 10g, above two points can be possible, using RMAN Convert Commands i.e. to construct or move a database from one OS to another OS i.e. Cross platform.
* When there is a requirement to clone a database on another test or development server, then take a full database mode export dump and create a database with the similar settings of target database, and import the dump in source database.

Simple Steps: how to perform a full database export using export utility.

* Use either system user or any other database user who has the EXP_FULL_DATABASE privilege.
* Set the NLS_LANG environment variable according the database character set and language details.
SQL> select * from nls_database_parameters

------------------------------ ----------------------------

Windows (Dos Prompt):


* Start the export with following command and options.

exp system/password@mydb file=c:\exportdmp\exp_fulldb_MYDB_27Aug08.dmp
full=y log= c:\exportdmp\exp_fulldb_MYDB_27Aug08.log

Note: This is just a simple export command to perform the full database export. I would request and suggest you to refer Oracle Documentations on export/import and their options. Check the references.

Help on Export and Import:

C:\> exp help=y
C:\> imp help=y

$ exp help=y
$ imp help=y


Oracle 10g :

Oracle 9i:

Oracle 8i:

Sabdar Syed,

Sunday, August 24, 2008

Do not invoke SQL*Plus with a password On UNIX and Linux platforms.

Most of us sometimes start SQL * Plus with a password on UNIX and Linux platforms without knowing security threat.

For example, an application user connects SQL * Plus by passing username and password on Unix/Linux Server.

$ sqlplus apps/apps@proddb

Here the sqlplus command parameters are very much available for viewing by all operating system users on the same host computer; as a result, password entered on the command line could be exposed to other users, as below.

$ ps -efgrep sqlplus
oracle 14490 2190 0 16:31:53 pts/5 0:00 sqlplus apps/apps@proddb
oracle 14493 14491 0 16:32:01 pts/5 0:00 grep sqlplus

So, there might be a chance for an intruder to know the user id and password, and can connect to the database using that credentials.

Then, following is the secure and best way of connecting SQL * Plus where the password is not exposed on the command line.

$ sqlplus apps@proddb
Enter password: ****

Or, even not to expose the username and connecting string.

$ sqlplus
Enter user-name: apps@proddb
Enter password: ****


$ sqlplus /nolog
SQL> connect apps@proddb
Enter password: ****

And also, do not use the password while invoking Export/Import Utility using exp/imp command line, and for any other command line utilities which you think the password will be exposed to others.

On Microsoft Windows, the command recall feature (the Up arrow) remembers user input across command invocations.

For example, if you use the CONNECT APPS/password notation in SQL*Plus, exit, and then press the Up arrow to repeat the CONNECT command, the command recall feature discloses the connect string and shows the password. So, it is advice *NOT* to pass the password while connecting to SQL * Plus on windows as well.

Your comments are welcomed.

Sabdar Syed.

Saturday, August 23, 2008

Cloning and Refreshing an Oracle Database

Dear Friends and Blog Readers,

I have been asked many times about the Cloning and Refresh process of Oracle Database by emails of blog readers and the users of the Oracle Technology Network (OTN) Forums.

Even though the information about Cloning and Refreshing a Database process available over web widely or has already been discussed. Here, in this post, I would like to explain and provide the information on the following Questions about Cloning and Refreshing of a Database with my simple terms.

Terms used in this post:

Source System - the system to be cloned - Production
Target System - the newly created (or cloned) system – Non Production
Production Database – PROD
Test Database – TEST
Development Database - DEV

What is a Database Clone?

* A database clone is an activity/procedure which is performed by every DBA on regular basis or when there is a requirement or request to do so from the different departments i.e. Test/Development teams.

* Cloning is nothing but creating a copy of production system in to a test or development environment. i.e. Having an exact image of production database in test area.

* Cloning is a procedure for preparing and creating a test or development servers with the copy of Oracle production database for testing upgrades, migrating an existing system to new hardware.

* A cloning process includes a copy of Oracle Home (Directories and Binaries) backup and Database (Database related files) backup to prepare the instance on another server.

* Though, it is possible to clone a database on the same server, Oracle doesn’t suggest to clone a database on the same server, where the production database is running.

What is a Database Refresh?

* A Database Refresh is also referred to as a database clone. However, we don’t clone Oracle Home rather we clone the Database as refresh.

* Refreshing a database is something like applying the changes or updates of production database to the database where the database is already cloned. i.e. let’s say you have cloned a database a month back, and now you are asked for doing refresh of a database, then you will perform the backup of database and prepare the clone the instance again on test server. This is nothing but refreshing.

* Refreshing of a particular table, group of tables, schema, or tablespace will be done using traditional export/import, transportable Tablespaces, or data pump methods.

* When an Oracle patch is applied on Production System, or in doubt, you have to prepare and clone the database again with the copy of Oracle Home (Directories and Binaries) Backup and Database (Database related files) Backup to prepare the instance.

* The difference between Cloning and Refreshing is that cloning process includes Oracle Home and database Clone; where as Refreshing process only includes database clone.

* If seen, the words, Clone and Refresh are used interchangeably for the sake of convenient.

When and why we Clone a Database?

* Generally production (PROD) database is cloned for various reasons and needs i.e. for something to be tested or something to be developed later those to be moved to production.

* It’s normal and quite common thing is that whenever there is any change or update to be performed and do not know the impact or effect after applying it on production (PROD), it’s required to be applied and tested on *NON* production database first (TEST or DEV), after the confirmation of change success, given by the users, then the changes will be moved to production.

* A Cloned test instance (TEST) for testing team/environment is exclusively used for testing the changes or issues which will be come severe on Production. Oracle Support gives the solution as fix when there is an issue in the database, so this fix needs to perform or apply on test/development databases.

* A Cloned development instance (DEV) for development team/environment is used for developing the new changes and then deploying the same on Production.

* A Cloned patch instance is used for patching to know the impact and the time required to apply the same on Production.

How to clone an Oracle Database and different ways of cloning.

There are many possible methods available for cloning a database, but each of them has pros and cons, and significance. Following are the methods.

Using Cold (Offline) Backup:

This is an easy and simple method to perform a clone of a database. This method requires your production database (PROD) needs to be shutdown gracefully, and take the backup of the database related files i.e. Data files, Control files, Redo Log files, using Operating System commands i.e. cp or copy. This is not possible where your PROD database is running 24/7 and should be available continuously for users.

For syntax and the series of steps to perform the clone using cold backup, refer the following URLs from the reference.


Using Hot (Online) Backup:

In this method, backup of the database will be done online i.e. without shutting down the database.

For this, your Production Database is must be in Archive log mode. For syntax and the series of steps to perform the clone using hot backup, refer the following URLs from the reference.


Using RMAN Commands:

Cloning can also be performed using RMAN Backups and RMAN commands and it’s also an easy method to perform so. The RMAN DUPLICATE command is used to perform the clone. Until Oracle 9i, to clone the database, it is required to be the Source and Target systems should have the same OS i.e. it is not possible to clone across the platform. But as workaround, using export/import can be cloning the database across the platforms. But starting from Oracle 10g the RMAN capabilities have improved immensely. Cross platform cloning/duplicating a database can be done using RMAN CONVERT commands.

For syntax and the series of steps to perform the clone using RMAN Commands, refer the following URLs from the reference.


Creating and Updating Duplicate Databases with RMAN

Cross-Platform Transportable Database: RMAN CONVERT DATABASE

Creating a Duplicate Database on a Local or Remote Host

Pre & Post Cloning Steps/Changes:

* Do *NOT* set the clone database name as good as production database Name.

* It’s *NOT* mandatory to have the initialization parameter values of cloned instance similar to Production Instance.

* It is *NOT* mandatory to have the cloned instance in Archive log mode. Because unnecessarily archive log files are generated, which consume the hard disk space? If at all, the cloned instance crashed and need to be recovered, it can easily be again cloned from the production.

* After the clone, change the system users passwords i.e. SYS & SYSTEM, and for any critical users passwords.

* Disable the jobs which are not required to be run in the cloned instance.

* Change any application users tables from the cloned database which are still referring the Production Database i.e. Server IP, Port Details, Printer Details etc,

Other Useful Links:

OTN Forums on Cloning:

Ask Tom Forums:

DB cloning -- what is it and why

Creating test environment from production box

Metalink Notes:

Note:245262.1 - Subject: Create a Duplicate Database with NOCATALOG on Same Node
Note:458450.1 - Subject: Steps to Manually Clone a Database
Note:388431.1 - Subject: Creating a Duplicate Database on a New Host.

Conclusion: These are only my views and outlines about cloning and need *NOT* to be the same with others or Oracle. One individual can still follow their cloning procedure documents which are there in place with them. I strongly suggest one to do the changes first in the test/development before doing it on Production. And also, use Oracle Documentations and Metalink Support for any kind of help.

Hope that this post helps you in understanding the Cloning and Refreshing activity of a database.

**Please leave your comments/suggestions about this post**.

Sabdar Syed.

Thursday, August 21, 2008

Q&A Session with me in Oracle Certification Professionals' blog

Dear All,

The Editor of 'Oracle Certification Professionals' blog - , had a Questions & Answers Session with me and published in his blogspot.

The series of Questions asked as below.

Q#1: Hi Sabdar, on behalf of the OCP blog readers we are delighted to have you today as our featured Oracle Expert. Please tell us something about you, your background and professional experience.

Q#2: New Oracle technologies are being introduced every year. Which technologies excite you most? What is your advice to Oracle professionals for adopting them?

Q#3: You are an Oracle Certified Professional on multiple tracks. How do you prepare for the certification exams?

Q#4: You are a very active member on the Oracle Technology Network Certification forum. Do you think certification plays an important role in the Oracle community? What advice/tips/suggestions do you have for the certification candidates?

Q#5: Your blog is one of the most popular Oracle blogs. Please tell our blog readers what topics do you discuss on your blog?

Q#6: Can you please let us know one habit that has contributed most to your professional success?

Take a look at the below URL where I had already answered to the Questions asked above.

Meet The Experts: Featuring OCP Sabdar Syed

Leave your comments please.

Sabdar Syed,

Monday, August 18, 2008

A good blog for Oracle OCA/OCP/OCE Certifications

I found a very good blog ( for them those who preparing for Oracle OCA/OCP/OCE, and seeking advice/suggestion/help in how to prepare for Oracle Certification. Mr. Mohan Dutt (OCP Advisor) is the owner of this blog. He is doing a fantastic job by collecting the wonderful and very useful information related to Oracle Certifications, and the people opinion, experience on the certifications.

I’m gonna add this blogspot in my frequently visit blog list.

Keep up the good work Mohan !

Sabdar Syed.

Wednesday, August 6, 2008

How to prepare for 1Z0-048 - Oracle 10g RAC Certified Expert Exam.

Dear Friends,

I would like to share my experience with the 1Z0-048 Exam – Oracle Database 10g: RAC Certified Expert, which I have recently taken.

I have passed the 1Z0-048 Exam “Oracle Database 10g: Real Applications Clusters Administrator Certified Expert”

About the 1Z0-048 Exam:

This Exam (1Z0-048) is one of the Certified Expert Programs. The Oracle offers the following list of Certified Expert Exams for Oracle 10g Database.

* Oracle 10g: Managing Oracle on Linux Certified Expert
* Oracle Database 10g: Administering Real Application Clusters Certified Expert
* Oracle Database: SQL Certified Expert

What is Oracle Certified Expert Program?

Click Here to know Oracle Certified Expert Program

Here I’m going to talk about the 1Z0-048 Exam - Oracle Database 10g: Administering Real Application Clusters Certified Expert.

Who is eligible for writing the 1Z0-048 Exam?

Those who are already certified in Oracle Database 10g/11g DBA
Those who are *NOT* certified already,
* They may first need to under go one training i.e. Complete one of the approved instructor-led online or in-class courses for either the Oracle University or from the Oracle Authorized Centers,
* Write the exam 1Z0-048 - Oracle Database 10g R2: RAC for Administrators.
* Submit the Hands On Course Requirement Form

For more information on this, please take a look at the below URL

To know more on the following

* Recommended Training and Preparation
* Additional Information & Resources
* Exam Topics

Take a look at the below URL.
1Z0-048 Exam Details

The Books and Documents I referred.

I have gone through all the ILT (Instructor Led Training) materials of the course “Oracle Database 10g: RAC for Administrators Release 2” which my friend has done this course from Oracle University. These guides have helped me greatly in passing this exam, as all of the questions came from these materials topics. I would strongly recommend and suggest referring the Oracle Instructor Led Training Books/Student Guides/Course Materials on Oracle 10g RAC and also Oracle Documentations.

What are Student Guides/ILT (Instructor Led Training) Materials?
Student Guides/ILT (Instructor Led Training) Materials

Oracle Documentations on Oracle 10g RAC

* 2 Day + Real Application Clusters Guide

* Oracle Clusterware and Oracle Real Application Clusters Administration and Deployment Guide

List of useful links for Oracle RAC for reference.

Click here for more Useful Links On Oracle RAC

Questions came from the following topics.

• Settings the Load balancing and failover clauses in the TNS entry, and remote logging parameters.
• Configuring ASM Redundancy Levels i.e. High, Normal and External.
• Adding and enable redo log groups on new node of the cluster. (remember the order of steps to perform)
• Undo Tablespaces in RAC.
• In what situations, we migrated from single
• Checking OCR Resource status and checking the relevant logs.
• Storage types which supports FRA (Flash Recovery Area).
• Post steps after the cluster database creation.
• Backing up the OCR and Voting Disks and recovering them (remember the order of steps to perform)
• ASM Instance Parameters.
• Benefits and implication of RAC.
• Utilities to verify Cluster and OCR Disks.
• Different Oracle Homes locations i.e. ORACLE_HOME,ORA_CRS_HOME,ORACLE_BASE
• Tools you use for patching on RAC environments.
• Using crsctl, srvctl, crs_stat with different attributes.
• Moving from non-rac database to RAC instances. (remember the order of steps to perform)
• Debugging CRS, modifying services
• Views to find the interconnect latencies.
• Difference processes of RAC.
• Removing and Adding the node in the cluster (remember the order of steps to perform)
• Location of server callout and notification scripts.
• Enable debugging for CRS, patching and rolling patch on RAC.

Many other Questions from the following things

OCR, Voting Disks,
RAC and Application VIP,
Services, DBCA, ASM

Others discussion on the 1Z0-048 Exam in OTN Forums.

Click here on Discussion of 1Z0-048 Exam

To know more on all the available Oracle Certifications and navigate yourself on the following options.

* Getting Started
* Certification Paths
* Exams
* Already Certified
* Support

Oracle Certification Program

OTN Forums on Certifications

Oracle Certification Forum

Update: Read my other post on "The books, guides, and materials used for my OCA/OCP/OCE Exam Preparation."

"The books, guides, and materials used for my OCA/OCP/OCE Exam Preparation."

Leave the comments if this post provides the relevant information and helps you.


Sabdar Syed,

I have passed the 1Z0-048 Exam “Oracle Database 10g: Real Applications Clusters Administrator Certified Expert”

Dear Friends,

I’m glad to say all of my blog viewers that yesterday evening I cleared the Oracle RAC Certified Expert Exam (1Z0-048 - Oracle Database 10g: Real Applications Clusters Administrator Certified Expert).

I would like to share my experience, preparation, references, other information on that exam in my next blog post, till then stay tuned here.

Update: Read my other posts on

How to prepare for 1Z0-048 - Oracle 10g RAC Certified Expert Exam.

The books, guides, and materials used for my OCA/OCP/OCE Exam Preparation.

Sabdar Syed.