1.29.2007

couple of 2 day new books added to Oracle docs.

I am sure every one consult/refer to Oracle documentation very frequently.
In addition to 2 Day DBA, today, I have found couple of 2 day books added to the Docs. Library of 10gR2.

These books provide background information for new users:

2 Day + Real Application Clusters Guide
2 day + Performance Tuning Guide.

This is really a good idea for the new users as instead of going across many pages to find the information, now, they can simply get digest concepts in few pages.

New users, who are keen to learn about RAC and Performnace Tuning, they simply can start with those books.

http://www.oracle.com/pls/db102/homepage


Happy reading,

Jaffar

1.28.2007

CONTROLFILE AUTOBACKUP should be TURNED ON??

RMAN is one of the very useful utility provided by Oracle for backup and recovery Purpose. Oracle online backups were introduced with Version 6, where tablespace must be kept in backup mode in order to take online backups.

RMAN was first introduced with Version 8 through which database server database can be backup. Since then, Oracle has enhanced RMAN features drastically by every release/version. I am not going to discuss neither the RMAN history nor the backup.

I would like to mention here, how enabling few default parameters of RMAN can save the life of dba significantly.

RMAN has following default parameters and its default values:

RMAN> show all;

using target database controlfile instead of recovery catalog
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default

CONFIGURE DEVICE TYPE DISK PARALLELISM 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO /app/oracle/dbs/snapcf_EHEALTH.f'; # default
I would be talking the benefits of CONTROLFILE AUTOBACKUP.

By default CONTROLFILE AUTOBACKUP is OFF. I would strongly recommend enabling CONTROLFILE AUTOBACKUP ON.

I remember in my early days of DBA job, a lot of notes/articles and many people use to suggest backup the controlfile immediately after any maintenance on the tablespaces, which was a good suggestion.

RMAN just takes away this head ache of backing controlfile after any maintenance on tablespace, when you turn ON CONTROLFILE AUTOBACKUP feature.

Benefits:


With a control file autobackup, RMAN can recover the database even if the current control file, recovery catalog, and server parameter file are inaccessible.

A control file autobackup lets you restore the RMAN repository contained in the control file when the control file is lost and you have no recovery catalog. You do not need a recovery catalog or target database control file to restore the control file autobackup.

Whenever you add a datafile/s, resize, increase/decrease the size of datafile/s or etc, controlfile is automatically backed up.

If CONFIGURE CONTROLFILE AUTOBACKUP is ON, then RMAN automatically backs up the control file and the current server parameter file (if used to start up the database) in one of two circumstances: when a successful backup must be recorded in the RMAN repository, and when a structural change to the database affects the contents of the control file which therefore must be backed up.


Conclusion:
You can turn the autobackup feature on or off by running the following commands through RMAN utility:CONFIGURE CONTROLFILE AUTOBACKUP ON;CONFIGURE CONTROLFILE AUTOBACKUP OFF;

Reference:

Oracle documentation – backup and recovery concepts.

http://download-uk.oracle.com/docs/cd/B19306_01/backup.102/b14191/rcmconc1006.htm#sthref261

1.27.2007

ORA-12537: TNS: CONNECTION CLOSED

As part of my OCM preparation, I have installed Oracle version 9i and 10gR2 respectivelyand also applied patch sets 9.2.0.8 and 10.2.0.3.
Created a test database on version 9i, enabled archived mode in order to practice backup andrecovery scinarios. Thought of having 9i database backup catalog in 10g database.
Therefore, I have created a small database in 10g. A rman user has been created in 10g for 9i databaserman catlaog.
When trying to connect to the rman user from 9i to create catalog, rman was complaining about thecompatibility, although, my 9i version is 9208, I was little bit puzzeled.'
Tried connecting through sqlplus of Oracle 9i to 10g database where I got 'ORA-12537: TNS: CONNECTION CLOSED'
Wasted good amount of time searching on the google and metalink, but, could not done with the error.
Later, I realized that I have listed 10g database SID with 9i listener.Upon moving 10g database SID with 10g listener, all went smoothly and the ORA-12537 gone away.

1.20.2007

You wanna participate in 11g Beta Program?

If you wanna try your hand on 11g beta, here is an url.
Register yourself and try your luck to test 11g beta.

http://otnbeta.oracle.com/bpo/prospects/index.htm

Jaffar

Bug 4200702 - BLOCK CHANGE TRACKING WHEN USING DIRECT LOAD

According to Metalink Note : 300989.1, when block change tracking enabled and using direct load operations, it is like to get an ORA-19694 on Oracle 10.0.1.x version specific to all the platforms due to a bug 4200702.

Possible Symptoms
~~~~~~~~~~~~~~~~~
RMAN-571: ==========================================================
RMAN-569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-571: ========================================================== RMAN-3009: failure of backup command on ORA_DISK_1 channel at 02/14/2005 ORA-19694: some changed blocks were not found in the change tracking file

Workaround would be disabling change tracking feature.

According to the note, this is fixed in a patchset 10.1.0.5 and one-off patches are available for 10.1.0.4 and 10.1.0.3.

I guess, who are on 10gR2 and enabled the BCT feature doesn’t have this bug.


Happy reading,

Jaffar

Desktop RAC - Virtually installed and configured.

I have successfully implemented a Desktop RAC scenario which is provided by Oracle at http://www.oracle.com/technology/tech/linux/vmware/index.html.

Initially I have downloaded all the four zip files required to test the Desktop RAC for Red Hot Linux, there are two zip files for Novell SUSE as well.

Note: you are required to register with VMware and Red Hot Linux in order to get the trail version of that software and a unique number.

Following are the two issues I have come across while implementing Desktop RAC.

1. One of the zip file download contains VMware workstation 5.3 download from the VMware site. Unfortunately you see a message at VMware site that VMware workstation 5.3 is no more available for download and it suggest you to download VMware workstation 5.5 version.
This is required because you need to get the unique key to validate the VMware installation.

I have first installed VMware workstation 5.5 and skipped the VMware installation part while running Oracle installation.

2. First two zips contain Oracle RAC software for Linux and each zip contains Disk1 folders respectively. The problem was that while unzipping zip files which has same folder names respectively, needed to rename and this cause problem while setup as the step looking for all the required files under the Disk1 folder. What I did was to cross compare the folder in the Disk1 folders respectively and copy the missing in to one Disk1 folder.

After couple of unsuccessful attempts, finally I have done with Desktop RAC. I can see that Red Hot Linux 4.0 OS installed, Oracle RAC (10gR2) with ASM configured.
Also, it gives you bunch of examples step-by-step in documentation to test the scenarios.
The implementation gives you two instances and a database named as RACDB with ASM configured.

This is good for the beginners to have RAC installed on a PC which doesn’t require state-of-the-art hardware.

I guess, this is not good for an experienced DBA. You can’t install CRS, create RAC database and configuration and etc.

For me, it’s a good chance to start and make myself familiar with RAC commands and do some testing before I go for any training or work with production.

If I come across any good issues, I will update on my blog.

Happy reading,

1.15.2007

New PC!!

Last night I brought a new PC with the latest configuration (I guess). PC contains 2 GB RAM, 250GB hard disk (7600 rpm), dual processor, DVD r/w and Intel original mother board.

Buying PC with the good configuration was a long pending task which fulfilled last night. This is the first step towards my OCM preparation where I would like test all the scenarios mentioned in the OCM Exam topics.

http://education.oracle.com/pls/web_prod-plq-dad/db_pages.getpage?page_id=41&p_exam_id=10gOCM

Second step would be attending the Oracle RAC course to satisfy the prerequisites of having attended two advanced courses conducted by OU. Although, I don’t like the idea two advanced courses attendance to meet the prerequisite, I have to attend against my will if I want to go for OCM.

Final step would be attending for OCM exam.

To meet the second and final step, I need quite a good time as I am paying it from pocket and I would be happier if my employer comes forwards and ready to sponsor for this, which won’t look possible because of the amount.

Hopefully, by end of this year, I will be in a position to invest money on this ** PROJECT** and appear for OCM.


Happy reading,

Jaffar

1.13.2007

Finally Switched to New Blog!

Finally, I was able to upgrade my blog to new blog format.
I was trying to upgrade my blog since the blogger beta was out and everybody can move their old blog to the new blog format.
Although, I could see the 'switchnow' buton on the blogger's main page, couldn't succeeded for couple of weeks just because whenever tried to switch, I was constantly getting, 'sorry message'. At last, after many unsuccessful attempts, today, I have seen 'Your blog is ready to switch' message on the Bloggers start page and immediaely I have switched the old blog to new blog.
It only took 5 minuts to switch.
Well, its time to play around with the new blog features.

Take care,

Jaffar

1.08.2007

Want to learn RAC????

I have come across of many request on serveral Oracle database forums and here and there asking about to have RAC env. on a PC for testing and learning purpose.
After some browsing, I have got two possibilities for the people who wants the same.


Basic Requirements:
Have a PC with good configuration, at least 1GB of RAM and good amount of DISK space.

Possibility 1:
Mr. Howard J Roger at his web size DIZWELL INFORMATICS has written an excellent articel on 'Building a 10gR2 Laptop RAC on Windows'' in which he greately explained about installation and maintenance of RAC on a PC. Following link will take you the article.

http://www.dizwell.com/prod/node/25

Possibility 2:

If you feel installing Oracle RAC, VMWARE and other stuff would be little bit hectice, at least, for the biginner, then, don't worry, Oracle has a ready made solution for you.

Desktop Data Centers: Oracle-on-Linux VMware Tool Kits

Oracle, VMware, Red Hat and Novell have teamed up to provide everything you need to run a full Oracle Database 10g on Linux environment on your Windows desktop—including the operational infrastructure and step-by-step instructions on how to use Oracle Database 10g and Oracle Real Application Clusters.

Note: These kits are for evaluation and development purposes only. Oracle will not support any deployments of these packages.

Currently the test cases are available on RED HAT and NOVELL only.

http://www.oracle.com/technology/tech/linux/vmware/index.html

Good books (in my view) are:

Pro Oracle Database 10g RAC on Linux Hardcover by Julian Dyke
Oracle 10g RAC Grid, Services... Paperback by Murali Vallath
Oracle Database 10g Real Application... Paperback by K Gopalakrishnan

Blog which discuss about RAC stuff:

Mr. Kevin Closson maintain's a good blog discussing about RAC stuff. Wroth to add to favourites or book mark his blog.

http://kevinclosson.wordpress.com/

Few good articles on RAC.

Mr. Julian Dyke wrote couple of good articles on RAC. It can be downloaded from his site.

http://www.juliandyke.com/

HAVE FUN WITH RAC!!!!!