The online material folder contains all lecture material from this years lecture. These are basically all slides used in the video clips or live sessions and are collected here for reference. You will also find a guide for installing an local environment for executing the code on the slides.
The presence folder contains the lectures from the last years. Other than this years lecture, it was not designed as an online lecture and the material might not be self-explanatory.
You can find all PostgreSQL / PostGIS lectures in this repository. Clone it onto your hard drive, or open a new RStudio project from Version Control -> git and enter the url of this repository: https://github.com/data-hydenv/lectures.git.