Concrete vs Generic – The story of a data model

The story of a project In the last project I was working on, we struggled a lot with our data model. The task was to replace an old product service with a new one. The old system has grown over time, was hard to maintain and the guys who made it have been gone a […]

DynamoDB with Kotlin and Spring Boot (Part 2)

About a month ago I published a short article about Kotlin, Spring Boot and DynamoDB. The post shows a basic setup for DynamoDB with Kotlin and Spring Boot. However, it doesn’t show a lot of aspects related to typical database implementations such as auditing or migrations. To fill this gap, I prepared an example project […]

DynamoDB with Kotlin and Spring Boot (Part 1)

During the last week I implemented my first persistence layer with DynamoDB using Spring Boot and Kotlin. As I stumbled over a couple of obstacles, I decided to summarize what I did and how my final implementation looked like. Dependencies The dependencies are pretty straight forward. I decided to use Spring Data for DynamoDB and […]

find vs. get

Three years ago I wrote a blog post with the provoking title “Don’t use Optionals for data repositories“. The post received a couple of critical comments and I had the feeling that I didn’t made my point clear. This week I stumbled over the same topic again, but from a slightly different point of view. […]

Using Spring Data for database views without an ID

A database view is a great way to prepare complicated data structures right in the database and present it in a more convenient way. We usually use database views to map our technical driven database structure (with a lot of tables and foreign keys) to a more business driven structure. This means that we might […]

ORA-28001: the password has expired

Today I came about a very annoying exception. After my development setup was running smoothly for the last six months, my application was getting database errors today. I know that I didn’t break something, so the problem had to be somewhere else – and it was: ORA-28001: the password has expired If you install an […]

3 ways of installing Oracle XE 11g on Ubuntu

During the last few days I struggled with installing Oracle XE 11g on an Ubuntu VM. And with “the last few days” I mean “the last few weeks”. Sad, but true. Here is what I learned about installing Oracle XE 11g on Ubuntu. But please note that I am not a Linux specialist nor an […]

Media Night Winter Semester 2013/2014

During the last summer semester, two friends of mine and I made a student project called TechTrends. TechTrends was a web application that let you search for articles and trends in the field of computer science. Based on posts from Reddit and Hackernews, it provided an intelligent search on a growing number of articles and […]

A GPS diary in four weeks with Play!

During the last four weeks I did another small project for one of my university courses this semester. The course was about ORM modelling and abstractions for databases. We did some exercies with Hibernate and discussed diefferent aspects about ORM modelling. At the end of the course, every student made a small web-project using a […]

Gelesen: Oracle 9i für Einsteiger

Oracle ist eines der weltweit größten Softwareunternehmen und Marktführer im Bereich der Datenbanken. In den meisten Informatikstudiengängen kommt daher einmal der Zeitpunkt, sich mit der Oracle Datenbank näher auseinander zu setzen. Welche Prozesse laufen im Datenbankenbetrieb ab? Was ist ein Redo-Log? Wie geht Oracle mit Transaktionen um? Was ist PL/SQL? All diesen Fragen versucht “Oracle […]