Online Free Courses from World's Best Universities

Coursera is offering courses free online. The courses are delivered from faculty members of top universities in the world. You may find more information on the courses at:

https://www.coursera.org/


Happy learning !!!

OOW-2012: Oracle 12c New Features

Blogging right from Tom's session "database new features". Here are the new features as they are discussed:

1. Identity Columns

Remember I blogged on this topic earlier.

2. Default on null

A default value is inserted into the column When it's null.

3. Improved defaults - metadata only defaults

Now add new default columns to a table on the fly. 12c does that for you.

4. Increased size limit for Varchar2 and NVarchar2

The column types can be upto 32k.

5. Row Pattern Matching

Efficient SQL functionality for reporting row patterns like identifying V and W patterns for your stock

6. Partitioning Improvements

Online partition movement without using DBMS_REDEFINITION. Efficient global index management during DROP and TRUNCATE partition operation.


7. Hybrid Histograms

Jonathan Lewis spoke on this topic. I think more information on this is available on his blog.

8. Session private statistics for GTTs

Table and index statistics are held private for each session.

9. Temporary UNDO
Undo for temporary tables can now be managed in TEMP. Reduces the amount of undo generated in undo tablespace and redo generation.

10. Pluggable databases

Read Roels blog for this one. He has a good blog post on this

http://roelhartman.blogspot.com/

Oracle RAC 12c: New Features

Blogging live from OOW session on "Enhancements in Oracle RAC". Following are few Oracle RAC 12c new features being discussed in this session as I post:

1. Application Continuity

2. Oracle Flex ASM
With this feature, database instances use remote ASM instances. 

3. Oracle ASM Disk Scrubbing
Checks for logical data corruptions and repair them automatically.

4. Enhancements to Policy-based Databases
Actively utilizes different sized servers

5. What - if analysis for server pool management

6. Standardized deployment and patching 
Introducing GHS, rapid home provisioning and gold images

7. A new "ghctl" command for better patching

8. Oracle Utility Cluster

9. Dynamic IP Management and name resolution made easy

10. IPv6 Based IP Addresses Support for client connectivity

11. Multi-purpose Installation

12. Oracle installer will run Fix-up scripts & "root.sh" scripts across nodes. You don't have to run the scripts manually on RAC nodes.



Exciting new features !!!

OOW-2012: Very Large Databases (VLDB): Challenges and Opportunities

I would like to thank all the attendees for attending my session "Very Large Databases (VLDB): Challenges and Opportunities". I am glad, the hall was full to it's capacity. :)

You may download the presentation by logging into OOW-2012 schedule builder. 

I request all the attendees to kindly rate my session by logging into OOW: Schedule Builder.

See you all !!!

PARALLEL_MIN_TIME_THRESHOLD Contradictions

PARALLEL_MIN_TIME_THRESHOLD initialization parameter controls which statements are candidate for parallelism. 

As per MOS, this parameter is set to 10 seconds while Oracle documentation claims that it is set to 30 seconds. Now who's correct ??? Seems like it's a documentation bug.

Below are the links to both Oracle documentation and MOS article:

• PARALLEL_MIN_TIME_THRESHOLD from Oracle Documentation
• Oracle 11g Release2: new parallel query parameters [ID 1264548.1]

Speaking at Oracle OpenWorld 2012

Well, it's time for Oracle OpenWorld again. This is the place to meet & learn from the industry experts. Glad I am making this year. 

This year I will be speaking on my experiences managing Very Large Databases. Following are the details of my session.


Session ID: UGF3662
Session Title: Very Large Databases: Challenges and Opportunities
Venue / Room: Moscone West - 2000
Date and Time: 9/30/12, 10:00 - 11:00



These are the activities on my OOW to-do list:

1) Attend lots of sessions
2) Oracle ACE dinner
3) Blogger meetup
4) Oaktable World


I’m looking forward to seeing you in San Francisco!

Win A Free Copy of Packt's Oracle Database XE 11gR2 Jump Start Guide eBook

I am pleased to announce that Packt Publishing is organizing a giveaway especially for you. All you need to do is just comment below the post and win a free copy of Oracle Database XE 11gR2 Jump Start Guide. Two lucky winners stand a chance to win an e-copy of the book. Keep reading to find out how you can be one of the Lucky One.

Overview of Oracle Database XE 11gR2 Jump Start Guide eBook

Build and manage the Oracle Database 11gR2 XE environment with this fast paced, practical guide. The book helps beginners to install, administer, maintain, tune, backup and upgrade the Oracle Database Express Edition.

Read more about this book and download free Sample Chapter:

http://www.packtpub.com/oracle-database-xe-11gr2-jump-start-guide/book

How to Enter?

All you need to do is head on over to this page and look through the product description of this book and drop a line via the comments below to let us know what interests you the most about these books. It’s that simple.

DeadLine:

The contest will close on 26-AUG-2012. Winners will be contacted by email, so be sure to use your real email address when you comment!

All the best !!!

Book Released: "Oracle Database XE 11gR2 Jump Start Guide"

I am pleased to announce my first book "Oracle Database XE 11gR2 Jump Start Guide" published by Packt Publishers. The book is available in two formats "Print Book" and "ebook".  

Please let your friends and colleagues know about the book. Have a look at the contents by following the below link:

http://www.packtpub.com/oracle-database-xe-11gr2-jump-start-guide/book

The book is available for purchase from the publishers website (www.packtpub.com) and other leading consumer websites like Amazon, Barnes and Nobles, Waterstones etc. 

Thanks to all my readers who have encouraged me to write this book. 

Oracle Database 12c - New Feature: Identity Columns

Well, Oracle Database 12c is not yet available but new features seems to be popping out in MOS. While troubleshooting Oracle Enterprise Manager Cloud Control 12c startup issues I came across Oracle Database 12c new feature called “Identity Columns”.

An Identity Columns is auto-incremented at the time of insertion just like in SQL Server. Going forward, I think you will not use Oracle Sequence anymore to generate unique values instead use Identity Columns.

For more information on this read:

HOW TO CREATE A TABLE WITH APRIMARY KEY USING AN IDENTITY CLAUSE [ID 1472346.1]

Happy reading!!!

Oracle Certified Master (OCM)

Today I received a congratulations email from “Oracle Certification Program” for successfully completing Oracle 10g OCM. Being an OCM is really an accomplishment in a DBA’s career. OCM is the most advanced database credential for an Oracle professional.

I still have to wait for another 2-3 weeks to receive OCM-Kit and to get my profile updated under “Oracle Certified Master Profiles”. 

DBUA Fails with ORA-17502 Error

While upgrade four-node Oracle RAC environment from 11.2.0.1 to 11.2.0.3, DBUA started to throw ORA-17502 error while creating a new SPFILE for the upgraded database. Not only did DBUA err out but it also deleted the existing SPFILE.

Below is the screenshot of the error:

In order to complete the upgrade process, we have to manually perform the following:

1. Re-create the SPFILE,
2. Complete Post-installation steps (like executing “utlrp.sql”), and
3. Re-create the Cluster Services

I later found out on MOS that this situation can be avoided by pinning the nodes as shown below:

$GRID_HOME/bin/crsctl pin css -n

To find out whether node(s) is pinned or not:

$GRID_HOME/bin/olsnodes -t –n

So, make sure that you pin the nodes before running DBUA to avoid the above errors.

Modifying SCAN Listener Port

It’s been awhile since I’ve published a post on my blog. I have so many things to share but not able to find time to share. Hopefully, very soon I will get back to blogging. Here’s a quick post on modifying SCAN listener port.

We have been having archive log corruption issues since we setup Data Guard (sometime last week) on Oracle 11gR2 (11.2.0.2). The physical standby database is receiving the archive log files but unfortunately not able to perform media recovery as the archive logs are in malformed state.

The customer is using CISCO switches between primary and DR. These switches have SQL*Net packet deep packet scanning/inspection enabled by default on 1521 port and this seems to be resulting in failed or corrupt-packets.

Below is an excerpt from the physical standby database alert log:

CORRUPTION DETECTED: In redo blocks starting at block 387073count 2048 for thread 2 sequence 8776
Deleted Oracle managed file +FRA/qtprdb/archivelog/2012_05_30/thread_2_seq_8776.366.784682159

So, this was the motivation behind changing the SCAN listener port and here’s how you do it:

1) Log in as the “grid” user (if you have installed Grid & database under single user “oracle” then use “oracle” user)

2) Make a note of current SCAN listener configuration:

[grid@rac-prod01 ~]$ srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN3 exists. Port: TCP:1521
[grid@rac-prod01 ~]$

3) Modify SCAN listener port to "1528"

srvctl modify scan_listener -p 1528

4) Restart SCAN listener to make the new port effective

srvctl stop scan_listener
srvctl start scan_listener

5) Finally confirm the change

 [grid@rac-prod01 ~]$ srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1528
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1528
SCAN Listener LISTENER_SCAN3 exists. Port: TCP:1528
[grid@rac-prod01 ~]$