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June 2012

Oracle Forms and Java 1.7 (don’t panic)…

The company I’m currently working for have a number of legacy Forms apps that will probably never get upgraded, so the recent news about JRE 1.7 and eBS being an issue (because of the Oracle Forms component)  made me worry just a bit. :)

Luckily, Kurt Van Meerbeeck has a good post about it here. Looks like there is nothing to panic about after all.

Cheers

Tim…

 

SQL Challenges

June 14, 2012 Dominic Delmolino put together a very interesting challenge.  The challenge is to produce something called a Pascal matrix using Oracle Database… more specifically, just SQL.  I had a vague recollection of Pascal matrixes when I read Dominic’s challenge.  Basically, the goal is to create a matrix similar to the following: The rule [...]

PX and system allocation

A few years ago (2007) I wrote about a problem that could appear when you mixed parallel execution with system managed extent allocation. A couple of years later I added a note that Christian Antognini had observed a patch in 11.1.0.7 that addressed the specific issue I had raised. Today, thanks to an email exchange with Christo Kutrovsky of Pythian, I can report that there is a variation of this issue still available even in 11.2.0.3.

The basic problem is that you can end up with a very large number of very small extents, leading to poor performance in parallel queries and a significant waste of space in a data segment. Here’s a simple, though not completely realistic, way to demonstrate the problem.

KScope 12

The ODTUG conference is only a couple of weeks away, now, so I thought I’d remind people that I’ve got three presentations, one panel session, and a lunch date booked.

I’ve also heard that Redgate is setting up an exciting stand where they’re not going to sell you anything (unless you ask for it), instead they’re going to do some real-time development of a new product based on feedback and suggestions from the people attending ODTUG.

How to use vi-style editing in SQL*Plus

This post is nothing new, and I created it after a little discussion on twitter about how to use readline support in SQL*Plus. The idea is not new, and I have compiled and used rlwrap for quite some time.

At the time, Frits Hoogland asked me why I didn’t use the EPEL package-and I had to admit to myself that I didn’t know the Extra Package for Enterprise Linux repository at all. But there is more to rlwrap and Linux I didn’t know, but first things first.

Installing rlwrap from EPEL

This is really simple-you can either add the EPEL repository to your /etc/yum.repos.d/ directory or simply download the rlwrap package and install it via RPM. A simple wget on your host does the trick. You can set environment variables when you’d like to use a proxy as shown here:

E4 2012 Enkitec Extreme Exadata Expo (Blue Jean)

I’m very pleased to have been invited to speak at the E4 2012 Enkitec Exadata Expo to be held in Dallas, USA on 13-14 August. It’s basically the first ever conference that’s dedicated exclusively to Oracle’s exciting Exadata platform. It should be a fabulous event, featuring some of the best Oracle talent going around, including Jonathan Lewis, Tanel [...]

eBS

Just in from Mark Bobak on the Oracle-L list server: a warning for the people who have to deal with the client environment for their eBS systems. (It’s likely that the relevant person in your organization has already received this message direct from Oracle Corp., but there’s no harm in double-checking.)

WordPress 3.4 Released…

WordPress 3.4 has been released. You can download it here, or use the automatic update for existing blogs.

Cheers

Tim…

Consultancy

I have a permanent job at the NetCracker‘s System Performance group. Recently I was offered to do one day job outside, on-site in another company, which coincidentally has an office close to NetCracker’s Moscow office. It was an opportunity to apply my skills in a completely different situation which I couldn’t miss; plus I’ve never done public presentations before and this was a good occasion to practice that. Here I’d like to write down some notes how the event went.

New SQL Puzzle

Sorry for the drought — to keep everyone’s mind fresh, how about a little puzzle?

Use SQL to create a symmetric Pascal matrix, with the output being (i,j,v). So that a Pascal matrix of size 4 would end up as:

1,1,1
2,1,1
3,1,1
4,1,1
1,2,1
2,2,2
3,2,3
4,2,4
1,3,1
2,3,3
3,3,6
4,3,10
1,4,1
2,4,4
3,4,10
4,4,20

Try to stay with ANSI SQL 2008 if possible — bailing out to other languages and functions is discouraged :-)

Efficiency is an interesting idea here, as it’s pretty easy to do this by brute force calculations of factorials for every entry — but where’s the fun in that?

Extra credit for solutions which can take in the matrix size as some sort of parameter.