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September 2012

OOW 2012 – Oracle XML DB Hands-On Lab (HOL10055)

I posted, as (my) tradition dictates, the Oracle agenda overview of XMLDB sessions during Oracle Open World 2012. I already signed up for the HOL10055 session but yesterday I also got a quick peek of it’s contents this year. And yes, I can promise you, it is a must go, if you are dealing with

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Announcing The Oracle Real World Conference. Attending Oracle OpenWorld 2012? Great, It Happens To Coincide With This Great Event!

BLOG UPDATE 2012-09-21: The conference organizers had to dodge legal bullets from Oracle Corporation for using the word Oracle. So, the name of the conference changed to Oaktable World:

This is just a quick announcement about a great conference hosted by the good folks at Delphix, Miracle and Pythian.

Please visit the Oracle Real World website for session and venue information.

I’ll be offering a session called “SLOB Why, How and What’s It Got To Do With Exadata.” Attendees will learn how to put SLOB to use for their benefit. They might even learn something important about Exadata as an added bonus.

Please follow this link to the website to learn more.

Histogram Generation

This really could be published in the Errata and Addenda of “Cost Based Oracle – Fundamentals”, but it’s more convenient to publish the whole thing here and just add a link to the Errata pages.

In chapter 7, on page 156, I gave an example of the type of SQL that Oracle runs (in the dbms_stats package) to generate a histogram. A sample of the code, and the plan from the 9.2.0.8 tkprof output, is listed below:

Enterprise Manager Cloud Control 12c Release 2…

Enterprise Manager Cloud Control 12c Release 2 was released a couple of days ago for all the major platforms. That in itself is not news any more, but the fact we are going to trial it at work as a replacement for our 11g Grid Control installation is.

It’s in my low priority task list, so I’m not sure I’ll get it all sorted before OOW12, but it is something to look forward too. I know it’s tragic, but I’m quite excited. :)

Cheers

Tim…

alt.oow

Once again there’s going to be an alternative (or extra) conference in San Francisco this year while Oracle Open World is running.

Arranged by Kyle Hailey of Delphix, with backing from Delphix, Miracle and Pythian, the Oracle Real Oak Table World conference will be held on the roof of the Moscone Center.

oracle in /etc/init.d

Just for my own reference Based on Tim Hall’s “dbora” post, but a little bit more to my licking, /etc/init.d/oracle (fna “dbora”). For info about the how/what/why, have a look a Tim’s post. Use “chkconfig” to install and set run levels in Linux. Use prio 97 97 so it will always start before or shutdown

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FBI Delete

A recent post on Oracle-l complained about an oddity when deleting through a function-based index.

I have a function based index but the CBO is not using it. The DML that I expect to have a plan with index range scan is doing a FTS. Its a simple DML that deletes 1000 rows at a time in a loop and is based on the column on which the FBI is created.

IOUG Collaborate 2013 — Call for Speakers Informational Webinar

As I’ve become Director of Communities for IOUG recently, I’m intimately involved in many aspects of leading the IOUG community. One of the areas the user group is pursuing all the time is finding new speakers, and it takes a lot of convincing before community members actually start presenting. There are many of you who have exciting projects and implementations to share but can’t quite convince themselves to actually present.

So, whether you are a total newbie presenter or a presenter with experience that didn’t present at IOUG Collaborate conference yet, you might find this webinar useful: IOUG: Call for Speakers Informational Webinar. I hope to see you select one of your projects or a technical area you are excited and knowledgeable about and send your abstract. Feel free to post any question if have them — I’ll make sure they get answered.

Exchange Partition, Virtual Columns And Column Statistics

Here is an odd bug that can lead to some nasty side effects when using the EXCHANGE PARTITION technique. It is probably there for a very long time, simply because it depends on the usage of virtual columns, and the basic technique of virtual columns was introduced way back in the Oracle 8i times with the introduction of Function Based Indexes.

The problem isn't the exchange partition operation itself, but the accompanying swap of object statistics information, in particular the column statistics.

Look the following sequence of DDL and DML commands and pay then special attention to the output for the column statistics before and after the EXCHANGE PARTITION operation:

DDL triggers

One of the partitioning features that Oracle introduced relatively recently was the “interval partition”, for example:

create table transactions (
	account_id		number(8)	not null,
	transaction_date	date		not null,
	transaction_type	varchar2(2)	not null,
	transaction_id		varchar2(10)	not null,
	amount			number(10,2)	not null,
	padding			varchar2(100)
)
partition by range (transaction_date)
interval (numtoyminterval(1,'MONTH'))
(
   partition p200801 values less than (to_date('01-FEB-2008','DD-MON-YYYY'))
)
;

When I insert data into this table for a partition that doesn’t yet exist, Oracle will work out which partition it should be and create it automatically before doing the insert. The benefit of this trick, of course, is that the DBAs and developers don’t have to write any code to add partitions in anticipation of time passing and new data appearing.