GraalVM – why a different VM?

If you read press around Java you’ll have come across references to GraalVM. So what is it and why would I use it?

There is an excellent podcast from Software Engineering Daily that digs into the subject and can be found here and here. But let draw out some of the reasons as to why GraalVM is interesting.

Whilst multiple languages on top of the JVM is nothing new, such as Scala , Kotlin, and (more...)

“Regulatorics: Offside is when the referee whistles” – I’m a speaker at #DOAG2018

Today my presentation is confirmed: “Regulatorics: Offside is when the referee whistles”. Maybe the German title will be  better understood: “Regulatorik: Abseits ist, wenn der Schiedsrichter pfeift”

The regulatory system has more and more influence on our software development.

Regulatory authorities, exteranl and internal Auditors are increasingly examining our IT and not longer only our business processes and balance sheets.
Some of them have better trained IT experts as we can find on the free market.

General standards such (more...)

Friday Philosophy – Despair of the Dyslexic Developer and Your Help Please

Like a surprisingly large number of people, I’m dyslexic. I’ve mentioned this before, describing how I found out I was dyslexic and also how I think it is sometimes used as an odd sort-of badge of distinction. I am mildly dyslexic, the letters do not try to “merge or run away” from my eye, if I hit a large word I am unfamiliar with I can visually chop it up and get through it. But (more...)

The Single Responsibility principle

The Single Responsibility principle is the foundation of modular programming, and is probably the most important principle in the SOLID set. Many of the other principles flow from it.

It is quite simple: a program unit should do only one thing. A procedure should implement a single task; a package should gather together procedures which solve a set of related tasks. Consider the Oracle library package UTL_FILE. Its responsibility is quite clear: it is for (more...)

Database Requirements for Modern Development

A while ago I wrote a paper talking about what key capabilities databases should provide for today’s software development world. The title of the paper is “Database Requirements for Modern Development“. It got published originally on the Oracle Technology Network and I just republished it here on my website. You can find it under:

A week of PostgreSQL

One of the attractive things of my job is this… Just a bit more often than every now and then, you get the opportunity to get out and meet people to talk about Postgres. I don’t mean the kind of talk I do every day, which has more of a commercial touch to it. – Don’t get me wrong, that is very important too! – But I mean, really talk about PostgreSQL, be part of (more...)

UKOUG Northern Technology Summit 2018

The UKOUG has run something called the Northern Server Day for several years. Northern because they were held in a northern part of England (but south of Scotland) and Server because the focus was the database server. Over the last couple of years the day has had several streams, covering Database, High Availability and Engineered Systems. So primarily a day for DBAs and their ilk.

This year the event has expanded to let in the (more...)

Why I picked Postgres over Oracle, part III

This is the final episode of this short series of blog posts on some of my drivers for moving to Postgres from Oracle.
Please do read Part I and Part II of the series if you have not done so. It discussed the topics “History”, “More recently”, “The switch to Postgres”, “Realization”, “Pricing”, “Support” and “Extensibility”.

In summary:

  • Part one focused on “why not Oracle anymore, so much”
  • Part two discussed on the comparison (more...)

Why I picked Postgres over Oracle, part II

Continuing this short series of blog posts on some of my drivers for moving to Postgres from Oracle.
Please do read Part I of the series if you have not done so. It discussed the topics “History”, “More recently” and “The switch to Postgres”.


In the last months, discussing Postgres with my Oracle peers, playing with the software and the tooling, I actually quite quickly realized Postgres is a lot cooler, at least to (more...)

Why I picked Postgres over Oracle, part I

As with many stories, if you have something to tell, it quickly takes up a lot of space. Therefor this will be a series of blog posts on Postgres and a bit of Oracle. It will be a short series, though…

Let’s begin


 I have started with databases quite early on in my career. RMS by Datapoint… was it really a database? Well, at least sort of. It held data in a central (more...)

How does IT work at

How does IT work at

Check part 1 of the video we created on How IT works at


#DOAG2017 wrap up


Another DOAG is over and here are my summary.

Day 1

As my presentation is planned for noon I arrived this year on the evening before, so I could attend the early sessions on 8:30.

Sten Vesterli: APEX, ADF, or ABCS? A real-life application built in 3 tools

He compares the development of a real application in APEX, ADF and ABCS. He don’t believe that ABCS is usable from end users and shows interesting (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...)

“#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...)

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...)

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:


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=""
                      xsi:schemaLocation=" (more...)