Overloaded Indexes (for ODC Appreciation Day)

ODC Appreciation Day is an idea that Tim Hall (aka Oracle-Base) came up with, to show out appreciation for the Oracle Technology Program (OTN)/Oracle Developer Community.

Fig 1 This is an efficient range scan

I want to show my support but rather than mention an Oracle “feature” I particularly like I’d like to mention a “trick” that I (and many others) often employ to help performance. That trick is Overloaded Indexes.

We can all (more...)

Provide access to #WebLogic DMS Spy Servlet for readonly users

For security reasons and to prevent the configuration drift it is recommendable to use read only for analyzing problems.

For read only access of configuration and logs WebLogic provides out of the box the group Monitors. Unfortunately you cannot access DMS Spy Servlet with this group, which is useful for analyse runtime values of the server. Only users which belongs to the Administrators group and therefore have full access can access DMS Spy Servlet and (more...)

Friday Philosophy – Sometime The Solution Has To Not Only Match The Problem But Also…

…The People!

When you design a system for end users, a good designer/developer considers the “UX” – User eXperience. The system has to be acceptable to the end user. This is often expressed as “easy to use” or “fun” or “Quick”. But in reality, the system can fail in all sort of ways but still be a success if the end user gets something out of using it. I’ve said it before and I’ll say (more...)

“#PL/SQL: Therefore, whoever binds forever: automate your tests” – I’m a speaker at #DOAG2017


Today my presentation is confirmed: “Therefore, whoever binds forever: automate your tests”. Maybe the German pun will be the better understood: “PL/SQL: Drum test-automatisiere, wer sich sich ewig bindet!”

I will speak over my experiences with following

  • several PL/SQL testing tools like at least
  • I will give you a demo of this tools and compare their capabilities for
    • architecture
    • branching
    • continuous integration
    • code coverage

If you (more...)

Friday Philosophy – “Technical Debt” is a Poor Term. Try “Technical Burden”?

Recently my friend Sabine Heimsath asked a few of us native English speakers what the opposite of “technical debt” was. My immediate reaction was to say:

I’d say (sarcastically) “proper development” or “decent designer” or even “what we did 25 bloody years ago when we were allowed to take pride in the software we created!”

But my next comment was less reactive and more considered. And that was to say that I did not (more...)

Hey JAVA-developer, why don’t you love your database

Why this post?

Partly, this blogpost is a result of a promise to Lukas Eder. Basically my vision adheres quite nicely to the “Thick Database” driven by Bryn Llewellyn and Toon Koppelaars who, understandibly, drive this from an Oracle perspective.
It –more than of course- also nicely fits EnterpriseDB or even vanilla PostgreSQL database landscapes.

There is apparently still so much confusion in the world on the how, why and what of (more...)

Containerization, do we need container-carriers?

In maritime logistics containers and container carriers are not really new.

Sitting in the plane, the following thoughts occurred to me…

In fact, containers in IT are a concept which is 1-on-1 derived from these physical containers.
We have seen and read many good and informative blog-posts and presentations about this. Obviously there is a lot of confusion about this as well. In my opinion you should be careful to mix and match too intensively. (more...)

Riga Dev Days 2017, new experiences in many ways.

Riga Dev Days 2017


It has been a while since my last blog-post.
One of the reasons is my shift from closed to open source software, databases more specifically. More on that in a later blog-post.

The reason for already mentioning this is this strange hybrid (what a popular word, these days) situation that I am in at the moment.
Thanks to the super enthusiastic, flexible and tenacious organization-team of the Riga Dev Days, (more...)

Compiling views: when the FORCE fails you

Darth-Vader-selfieThe order in which your deployment scripts create views is important. This is a fact that I was reminded of when I had to fix a minor issue in the deployment of version #2 of my application recently.

Normally, you can just generate a create or replace force view script for all your views and just run it in each environment, then recompile your schema after they’re finished – and everything’s fine. However, if views depend (more...)

#Javaland 2017 wrap up

Yes – I did it again and attend Javaland conference in Phantasialand Brühl.

It was not easy this year to concentrate on the sessions because of the hottest march of the last 100 years. But the quality of the sessions beats the weather. Maybe again my invest in reading the abstracts and filter the sessions before the conference has payed off.

Day 1 Conference

Jens Schauderdocumentation & slides with AsciiDoc, Git, Gradle and Reveal.js


#DEVCAMP17 wrap up


Yesterday I attend the annual barcamp DEVCAMP of the DOAG development community. There are mostly developers with SQL, PL/SQL, Forms & Reports, ADF, JET background and some Java, Javascript and APEX developers too. And not to forget: 1 dba and some managers. Here are my summary.

I arrived on evening before just in time for the life cooking event and later at the bar to meet lot of the people I already know and some new too.

The morning begins with (more...)

#Oracle cutting in inspiration and new business?

Over the many years Oracle has been leading the database world, I guess they are now taking something of a wrong turn.
Let me briefly fill you in on my thoughts.

Basically I see two “minor” shifts that are significantly indicative of this:

  1. Oracle Standard Edition 2
  2. Oracle ACE Program

Okay, so you might think I am crazy, but let me try to explain.

Oracle Standard Edition 2

Sometime last year, the long expected, (more...)

Virtual Development Server: Provide Docker images in docker registry for Oracle via Jenkins

This is a follow up to earlier Virtual Development Server: Provide Docker images in docker registry for Oracle XE Database and others.

We now try to automated build of all needed images as soon as Oracle GitHub Sources changed or we need to build our Vagrant VirtualBox again from scratch.

After we have already installed Jenkins we now install first some needed plugins.

We select explicit plugins at Jenkins Configuration: Pipeline and Pipeline Stage View Git SSH Slaves and wait for the install process Later we add Blue Ocean Beta via "Manage Jenkins" -> "Manage Plugins" . After all is installed we restart Jenkins.

After this we create our Jenkins pipeline via “New Item”.

We give it a name and select pipeline. As we do not own the git repository and cannot create a hook there, we create a simple scm poll schedule. Then we add our pipeline script.

Here is the script (more...)

Virtual Development Server: Install Jenkins for Continuos Integration / Delivery / Deployment


For automation of all of my processes I need Jenkins in my development server.

First I had installed Jenkins as Docker container via Vagrant Docker provider. But with this architecture it was very complicated to create docker images and run Docker containers on the Docker host, in this case my Vagrant Virtualbox.

So for simplification I have decided to install Jenkins with the provisioning of the Vagrant Virtualbox via a shell provider in my Vagrantfile:


#DOAG2016, definitely a crazy week.

#DOAG2016, the largest Oracle Community gathering in Europe. Taking place in Nuremberg, at the Nuremberg Convention Center NCC, one of the more impressive places to hold such a conference, towering 4 stories high, with a big central atrium!!
It is a huge effort to get all of this together!

In this blog-post I want to highlight some of the crazy things I experienced this week… And… I did try to follow my own schedule (more...)

Fix “BEA-000394: Deadlock detected” for Weblogic with ADF Applications

If you try the newest version (or maybe earlier versions too) you see, that your managed server does not restart, when

  • you have deployed your ADF application(s)
  • you try to restart the managed server with ADF
  • you use intentionally or not shared libraries in your weblogic-application.xml (see example below)
<?xml version = '1.0' encoding = 'UTF-8'?>
<weblogic-application xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                      xsi:schemaLocation="http://www.bea.com/ns/weblogic/weblogic-application http://www.bea.com/ns/weblogic/weblogic-application/1.0/weblogic-application. (more...)

#DOAG2016 wrap up


Another DOAG is over and here are my summary.

Day 1

Unfortunately the early train from duesseldorf arrives not before 9:30, so I missed the first morning slot. But on the other hand I this was the slot where I had to decide between 8 presentations, which I’m interested in.

The first soft skill presentation was about creative techniques beyond brain storming. The mentioned 3 techniques was all unknown for me, maybe I give it (more...)

Building Classrooms in the Cloud

Jumpbox Lab Server

Let’s face it: education without interaction is about as effective as shouting origami instructions at a lumberjack who is cutting down trees. Sure, your informative lessons will come in handy when the product of their work finally becomes paper, but it will be long forgotten and ultimately worthless by then. The only way a student is going to learn is if they can put (more...)

Virtual Development Server: Provide Docker images in docker registry for Oracle XE Database and others

For later creation of containers as needed in the deployment process we have first to build docker images whenever we do not find suitable one in docker hub.

For most of my development I need a oracle database. On the internet you can find a lot of Dockerfile’s for this, but no ready image. This is because for running a database you have to accept a license and this happens when you download the installation (more...)

Real Push Button Refresh with Raspberry Pi

Push Button

In this post, we’re going to perform a push button refresh of an Oracle Database, Application Express (APEX) installation, and Tomcat webserver.

“But Oracle Alchemist,” you’re probably thinking, “we know about that. You’ve told us about how Delphix can provision and refresh data.” And yes, you’d be right. But I wasn’t done yet.

We’re going to perform a refresh of an Oracle Database, APEX installation, and Tomcat running in Amazon Web Services, replicated from (more...)