November 2014

AUSOUG conference Perth

The annual two day AUSOUG conference in Perth is well underway, and so far, its been a wonderfully successful event. In particular, we Australians are notorious for not really getting into the networking thing, so conferences often have a lot of ‘awkward silences’ when sessions are not on, and we are meant to be (god forbid) *talking* to each other :-)

But this year has been different. Lots of banter, lots of discussion. Also, the AUSOUG committee got it exactly right this year. The venue is just the right size, the rooms are the right size, the timings of the sessions and transit times were spot on. It is a real credit to them – it shows how much they are listening to the speakers and attendees feedback.

About Oracle’s Code of Ethics, MOS Confidentiality Clause, and Content Stolen from My Website

I strive to keep the number non-technical posts on this blog to the minimum. However, there are days when a non-technical post has to be written. This is one of such days.

Oracle Corporation, concerned about legal and ethical issues, not only provides to its employees a document entitled Code of Ethics and Business Conduct, but also expects that every employee adheres with the standards that the document sets. For the purpose of this post, I would like to quote part of the “Intellectual Property” section:

A simple 12c query with a cool result …

Its not immediately obvious the significance of this query…but trust me…you’ll love it :-)

What Day Is It If You Only Specify The Time?

What is the date if you only specify the time when you populate an Oracle date column (or variable)?

That was the question that came up a few days ago in the little DBA team I am currently working in. Of course, the question was posed by the “junior” (who is damned smart at this stuff as he keeps asking questions like that) and the answer from us two old hands was… “Ohh!… hang on… errr….”

A little discussion then occurred. One of us suggested it would be “today”. One of us suggested it would be the Julian 1 date (4712BC). Both of us then stated it was an easy thing to test and the PROPER answer was “just try it and then you will know for sure”. We were right {and, of course, wrong} – as in with a simple question like this you don’t need to google the question (so “hello” to anyone googling the question and finding this page!) you just try it:

The junior tried it and…

Level of Detail is Hard

Earlier this week, I attended the 2014 East Coast Oracle Users Conference in Raleigh/Durham, NC. The conference was awesome. It was great meeting new attendees as well as seeing a few of the regular, familiar, faces in our community. That being said, if you’re in the area, I’d certainly recommend attending. Likewise, at the conference, I presented, […]

Cardinality Feedback

A fairly important question, and a little surprise, appeared on Oracle-L a couple of days ago. Running 11.2.0.3 a query completed quickly on the first execution then ran very slowly on the second execution because Oracle had used cardinality feedback to change the plan. This shouldn’t really be entirely surprising – if you read all the notes that Oracle has published about cardinality feedback – but it’s certainly a little counter-intuitive.

#CloneAttack online ! (and in person at #ECO14 & #DOAG14)

I’ll be at #ECO14 today in Raleigh,NC. Catch me in person to get a copy of #CloneAttack. I’ll also be at #DOAG14 in Nuremberg Nov 18-20 running an official #CloneAttack along side of #RacAttack and #RepAttack. Will also be at #BGOUG in Sofia Bulgaria Nov 14-16.

For online #CloneAttack info read on:

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We are starting a limited publicly accessible download of a trial version of Delphix and lab.

ECO 2014 Slides

Just a quick note that I posted slides for the 2 talks I did at ECO in Raleigh this week:

Keynote: Creative Problem Solving (for Oracle Systems)

In-Memory In Action (slides by Tanel Poder) :)

Great crowd. I really enjoyed myself.

Note: You can also find other presentations on my Whitepapers/Presentations page via the link at the top of the screen.

Little things worth knowing: ORACLE_SID, instance_name and the database names in Clusterware

If you ever wanted to know how Clusterware works with registered database resources, read on! It takes a little while to get your head around the concepts of the ORACLE_SID, the instance_name and the database name as well. And how Clusterware deals with all of them. Although this post has been written on 12.1.0.2.0 on Linux, it should be applicable to 11.2 Clusterware as well. Oh and by Clusterware I mean Grid Infrastructure of course ;)

Why would you want to care?

Most deployments I have seen use the simple formula: ORACLE_SID = instance_name = db_name, especially in single instance deployments. RAC One Node and RAC databases are slightly different as their instances are usually named db_name where is the n-th instance in the cluster. What however, if you want to have separate SID, instance name and database names? I keep things simple for now and don’t throw in a different db_unique_name…

Jonathan Lewis explains Delphix

OOW 2014 was the best so far for me and a whirl wind.  After not having a presentation accepted since I left Oracle 10 years ago, I got not only a presentation accepted but 3 presentations accepted. Woohoo! Two of my presentations are available on youtube at

On top of that with the awesome support of the Oaktable, Delphix, Pythian and Enkitec , I was able to secure a great venue for the 3rd annual Oaktable World at OOW where we had the leading Oracle performance and internals experts speak for 2 solid days. You can see videos of the Oaktable World presentations at