Oh my... sorry everybody for wasting your time, the problem is solved. I tried the solution with the search index configuration. It didn't work for some reason, so I did some more debugging. During that I found out that there was a bug in my code that caused the mimeType of this binary file to default to text/plain. No wonder it ran out of memory when trying to read a line of text from a huge binary file...
Sorry again for this and thank you all for the great support. Best regards, Johannes
