Monday 13 August 2007

Oracle Database FAQs

Question: I am new to Oracle. What should I do first to get started
Answer: Find and read the Oracle Documentation relevant to your area of interest in Oracle. Oracle Product Documentations are Online at the Oracle website.

See Getting Started: DBA and Oracle Documentation Libraries

Question: Where can I find Oracle Database Documentations?
Answer: The following links will help you

Oracle® 11g Documentation
Oracle® 10g Documentation
Oracle® 9i Documentation
Oracle® 8i Documentation
Oracle® 8 Documentation
Oracle® 7 Documentation

Question: Can I easily install the Software and create the database without using the installation guides
Answer: It is important to read any product's documentation before you start installation. It saves you and your organisation the time you will spend searching the internet and forums for answers to avoidable problems. Most of the Software and Hardware requirements and known issue will be stated in the Installation Guide, ReadMe or Release note.

Questions: Can I skip any of the prerequisite checks?
Answer: You should only skip them whee and when advised by Oracle. The fact that installation completed successfully after skipping some checks does not guarantee that a related problem will not show up later.

Questions: How can I upgrade from Oracle Release A to Oracle Release B
Answer: Every Oracle Release comes with an Upgrade Guide and releated release notes. There is no need for guess work on it. The first thing to do is to pickup up and read the these documents before you start.

Question: When I have two Oracle Homes, which listener should I use
Answer: Use the listener of the later Release.

Question: I have got an error while running a program. What should I do first
Answer: Look at the Oracle Error Messages Manual as the first stop. If you the exaplanation did not help, then search Oracle Metalink and Oracle Forum for similar errors before you post any questions. If searching does not help, then post a question in the correct forum. If you cannot find a solution, then Open Service Request (SR - formerly TAR).

Question: What information do I need to provide when posting a question to Oracle Metalink or Oracle Forum
Answer: State your Product, Version, Release, Platform/Operating System. Mention the latest Patchset and CPU applied. Mention what you did or changed before the error occurred and what you have already done after the error occurred. Ensure you do not write in capital letters as it indicated shouting.

See Oracle Forums Etiquette

Question: Do you have any Hint on Oracle 11g Instalaltion?
Answer: The following links will help you

Oracle® 11g Database Hints


Question: Where can I find Enterprise Manager Documentation?
Answer: The following links will help you

Enterprise Manager Documentation Library

Question: Where can I find Oracle Examples?
Answer: The following links will help you

Oracle® By Example (OBE)

Question: Where can I find Oracle Database Error Messages?
Answer: The following links will help you

Oracle® Database Error Messages

Question: Where can I find information on Duplicating Databases?
Answer: The following links will help you

Creating and Updating Duplicate Databases with RMAN

Question: Where can I find information on Application Server Single Sign On?
Answer: The following links will help you

Configuring Enterprise Manager for Use with OAS Single Sign-On

Question: Where can I find information on Enterprise Security?
Answer: The following links will help you

Configuring Enterprise Manager for Use with Enterprise User Security

Question: Which of the documentations is equvalent to quick guides for DBAs
Answer: In the Documentation Libraries, look fo rthe 2 Day DBA guides. They are simpler to use than the main big guides.

You can use the links at the right pane of this blog to find other topics of interest.

All the best in your Oracle role.

Thursday 9 August 2007

Tackling the Month End Processes

Getting ready for the month End Processes for one of our clients is one of the tasks that keep us busy at this time of the month. Although the tasks involved in the processes have been automated and streamlined, you still have to ensure that things go smoothly.

This Month end processes will started on the 7th and will be completed on the 16th. My part will be 1 day before the d-day and the d-day itself (14th). Other post tasks will be monitoring what other teams are doing.

It is fun as usual, but could be a different story if things go wrong.

Fingers Crossed.

Wednesday 8 August 2007

Client and DBA Knowledge Transfer

Will be spending 2 hours in a knowledge transfer session with team members this morning lead by one of the gurus here. This I understand will cover all the services provided for the new client as covered in the service definition with most concentration on the actual Database Adminitration tasks to be provided.

One of the team members just joked "take an anti sleeping tablet with you". Yes, it helps sometimes. You know what I mean.

But I am looking forward to the sessions. Will close in time for lunch though.

Tuesday 7 August 2007

Using atomic_refresh Parameter in Oracle Materialzed View Refresh

I was doing a refresh today that involves materialised views from the second schema and a colleague asked me this question. I thought I should share oracle's answer to it.

Why use atomic_refresh=>FALSE?

SQL>execute dbms_mview.refresh('schema.mv_name','C',atomic_refresh=>FALSE);


"Refreshing single MV is not atomic even if ATOMIC_REFRESH = true (the default). This can lead to wrong results in sessions querying against the materialized view as the row count can suddenly change to 0 (as the refresh truncates the MV). An atomic refresh should not affect read consistency in this way"

In 10g a Complete Refresh of single Materialsed View will do a delete instead of truncate. To force the refresh to do a truncate instead of a delete parameter atomic_refresh must be set to false.

That means that since it will be doing truncate instead of delete, the refresh will go faster.

"The dafault value for atomic_refresh in dbms_mview.refresh in 8.1.7, 9i and 10g is TRUE, but in 8i and 9i Oracle does not check the atomic parameter, but because of some enhancements it will do this in 10g"

Just Another Good DBA Day

Just hoping it will be a more interesting day today.

Have just completed my usual morning checks and trying to deal with a support request that have no useful detail on it. Yes, the usual DBA requests that have not got enough information to determine what and where. Sometimes it is like the question in Oracle Forums that you have to ask "What release and Which platform" etc.

This particular request for users to be created without saying where or for which environment. It may not even be within the service deifinition of the projects I support, could be someone else's responsibility or could even be for a different client/account. As usual, I have asked questions and forwarded it to someone who might know for advice.

Well, I am currently working on a Database Shared Service Centre with various clients/accounts to support. This makes the job interesting, but sometimes more demanding.

It's nice a sunny here this morning, but may get rainy later in the day because it is beginning to show some signs of the sun disappearing. Yesterday was good.

Have a good day.

Monday 6 August 2007

Ask DBMS Direct

I thought I should do something more interesting apart from regular work. Then I said, "Why not start a blog that will help other DBA, Developers and Users".

It has always sounded like an interesting idea. So, here I am.

I will try as much as I can to update this blog. If you find it boring or uninteresting any day do not be sad, visir another day.

Welcome to my blog.