Analyze That

As Jonathan Lewis commented on my article Clustering Factor: Row Migrtion’s Victim, there is even more to say about the difference between the good, old, and deprecated ANALYZE statement and the DBMS_STATS package. Jonathan mentioned that the CBO is using the CHAIN_CNT value in the statistics, if present, and suggested to try my “trapQL” after analyzing the base table in the old fashion.

For easy C&P I the complete new script to try:

CREATE TABLE row_mig1 (
  a CHAR(2000),
  b CHAR(2000),
  c CHAR(2000),
  x NUMBER      NOT NULL,
  filter NUMBER NOT NULL,
  CONSTRAINT row_mig1_pk PRIMARY KEY (x)
) ENABLE ROW  (more...)

More than Iron Man – Oracle and Marvel

At the beginning of April 2010, Oracle, using the buzz around the release of Iron Man 2, kicked off a worldwide advertising campaign focused on introducing the powerful combination of Oracle and Sun. This includes old school billboards and commercials on a variety of old and new media platforms...

(more...)

NVARCHAR2 versus VARCHAR2

I've been coming across more and more databases using NVARCHAR2 instead of the more usual VARCHAR2 data type and found some issues.

First, I had issues inserting data from an NVARCHAR2 column into a table where the corresponding column in the other table has a data type of VARCHAR2.

Second, I had an issue joining tables together where the same column was defined with a different data type, one being NVARCHAR2 and one being VARCHAR2.

Here is the way I solved these issues:

Inserting NVARCHAR2 into VARCHAR2
If you try inserting data from an NVARCHAR2 column into a table where (more...)

How to write a simple yet “bullet-proof” object cache

…continued from a previous post, by Eduardo Rodrigues As promised, in this post, I’ll explain how we solved the 2nd part of the heap memory exhaustion problem described in my previous post: the skin...

This is a summary only. Please, visit the blog for full content and more.

Java Decompiler

I have a new tools to share with you : JD GUI

http://java.decompiler.free.fr/?q=jdgui

It's one of the must-have if you need to figure out why things are not working the way you expect them to work...

After two days searching for a NPE, which was not (more...)

The Age of Scroogle

I hear that the Age of Facebook is upon us. While I was busy tending to my identity and access tomatoes, the new dawn has been declared. Apparently right outside my window there be walking people whose identity has been sucked into a space-time deviation yet they're blissfully unaware of this. For those of you in the know (read: in the possession of a secret handshake), the Age of Aquarius is really where things have been happening for a while but I digress.

Astrology and social networking aside (wait, aren't they one and the same?) I think (more...)

Oracle’s Database History

I have been working with Oracle since version 5 (1986). It is always interesting to try to remember when certain feature was added to the database. I found a link to an Oracle Magazine article which lists Oracle's database history and more:

http://www.oracle.com/technology/oramag/oracle/07-jul/o4730.html

Update under the hood … and some extreme side effects

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At first glance, this topic may look trivial, but may be the source for severe performance issues, unnecessary maintenance tasks and/or storage waste.

Yes, you can say "update is so basic, why I should care about it?!", well it may be some cases when using update without care, things may get ugly. I found it playing with my old friend ALTER SYSTEM DUMP BLOCK and a few inserts and updates, over a table with a few columns, two of them VARCHAR2 type.

This was done on an Oracle 10.2.0.4 release database, (more...)

ExcelDocTypeUtils API Guide

I finally broke down and documented the ExcelDocTypeUtils PL/SQL API  in a 34 page document. Sorry about the long wait …

Here it is:  (opens in new window):ExcelDocTypeUtils API Guide

ExcelDocumentType: New Feature … Freeze Column Header Row

I  added a new feature to  the ExcelDocumentType object and ExcelDocTypeUtils package that will allow report developers to freeze the column header.  This means that the column header row will stay stationary (not scroll away) as the user scrolls through all of the data rows in the worksheet.  I have added an example of how to use this feature to the EmployeeReportDemo.sql file in the code bundle.

(Download the code here:Code)

COLLABORATE: Oracle ACE Dinner

Uncategorized
| Apr 19, 2010

Twitter to the rescue again.

I was at the OAUG 20th Anniversary Party where I consumed my usual 2 beers (albeit larger than normal beers), when I noticed this tweet by Brian “Bex” Huff.

With the help of a couple of very nice conference attendees, I was able to locate the establishment. They warned me that the restaurant might not allow me in as I was in my travel attire (flip flops), but they did. Pretty casual everywhere around here.

Anyway, this was my very first Oracle ACE gathering. I got to meet, among others, Iggy Fernandez, Sunil Ranka and Bex. I also met Vicki who is the Oracle representative who runs the program. She actually went to high school near me in Denver.

Although I may or may not have had too much to drink, I had a good time. Floyd Teter has introduced me to just about everyone in the world and I’m struggling to remember everyone’s name. If my phone or camera would work, I could probably take a picture and quickly tag it with their name. I need a system.

Anyway, I had the steak which was delicious.

Looking at that picture though…the presentation doesn’t look too appealing…I can’t think of a couple of disgusting things that it looks like. But I was plyed with beer and didn’t care much. Like I said, it was delicious.

I also got to meet Arup Nanda, who’s New Features guides/tutorials I’ve used a million times to learn something new. Not really sure I belong with that crowd…but I’ll take full advantage of the opportunity. 🙂

Oracle Critical Patch Update – April 2010


The 2nd critical patch update for 2010 (CPU April 2010) has been released by Oracle yesterday. Critical patch updates mostly contain fixes to security vulnerabilities plus it would have non-security fixes too. This critical patch update contains 47 new security fixes across all products which includes 7 for Oracle database. For the first time, CPU includes patches/fixes for Sun products. Please review the following URL to see if the product you are using requires this patch or not.


The next critical patch update (CPU) would be coming in July 2010.


Certain things in this world

"In this world nothing can be said to be certain but death and taxes."
--Benjamin Franklin

Starting Oracle Coherence 3.5 book review

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Past Friday, Packt Publishing gave me a copy of his newest "Oracle Coherence 3.5" book, which you can find clicking the book cover image below.



Coherence is a Middleware product from Oracle which main purpose is being a high performance Cache on the 2nd tier, thus improving performance reducing unnecessary traffic or requests to the database server. On next weeks my comments on this book...




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Our brain does not work in a linear or list-like manner (yeah.. not like the guy on the right). From the textbooks and blogs that we read everyday we are all aware that print is laid out in a series of lines or rows…

but our brain is multidimensional…

the information as it is being absorbed could be travelling sequentially to our brain, but internally it is not being serviced in simple lists and lines. There is a complex process of sorting and selecting and the whole network of words and ideas are being juggled and interlinked in order to (more...)

Oracle Exadata/Database Machine… nice to meet you

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During the last four or five weeks I've had the rare privilege of working with this amazing piece of engineering, the Oracle Database Machine.

Engaged during deployment of it, I've faced the setup steps on the SW side, applied upgrade patches & side-to-side with Oracle Sun engineers bringing this marvel to life... it's just exciting, watching all the slightly-bluish-green leds showing HD activity or admiring the most precise cabling I've ever seen... there is just one word: precision. I remember my first experience with an HP XP12000 SAN, five years ago, being not that exciting (more...)

New Open Source Offering: OWA Session Cache Utility

I have added another open source code/utility offering to the site. It’s called the OWA Session Cache Utility.

The OWA Session Cache utility is a custom add-on for MOD_PLSQL and DBMS_EPG DADs that provides the ability to maintain a stateful session in a Web PL/SQL Toolkit application. The utility has features similar to those found in Java Servlet based applications such as session cookie (holds session id), ability to set session timeout period, expired session management, the ability to store and retrieve session data using AJAX enabled JavaScript, and a garbage collector to clean up the session cache.

To find (more...)

Oracle + Sun + Iron Man 2: Awesome!

A cool Iron Man 2 teaser...

This is a summary only. Please, visit the blog for full content and more.

EclipseLink Summit 2010

In an effort to increase the community of committers and contributors with in-depth knowledge of EclipseLink we have decided to host a 3-day Summit. The goal of this Summit will be to exchange detailed technical information and discuss future direction for the project and its persistence services.

All interested parties are welcome to participate.

More info on Summit is available here.

Doug

Oracle RAC One Node – What is it?


I am reviving my blog after a long time. Hope I will be much regular. Some of my posts have been popular and received good feedback. Thanks to all of you who visited this blog and I am glad that the information has been useful.

I was looking for some information on Oracle RAC One node, early this year and did not find much. I thought to do a post on my views/opinion on this latest option introduced by Oracle. I am yet to get hands-on with this option. Please leave your comments/feedback if you have different opinion/experience with this (more...)