Kafka's "Auf der Galerie" is, all told, two sentences long.
It is theoretically possible to have a never-ending sentence in German.
Were you to write that sentence, it would, by definition, need to cover everything. "But then again, no", I guess we would need to add to this definition that the sentence would need to be an 'irrational' sentence (in the sense in which a number is irrational) - never ending and non-repeating.
This sentence would, in the end, I think, be Borgesian and the task of writing it, Sisyphean.
When I was wandering the library stacks last week (the Golda Meir library, that is, not Borges' or Babel's) I came upon the diaries of Franz Kafka. I opened to the entries, first randomly, then closest that day's date (July 14th, though I ended up reading the entries from May and September as Kafka seemed to have taken that summer off from writing). It occurred to me that Kafka was a bit of a whiner and his journals had no real academic or artistic merit, but I'm quite sure, if I were so inclined, I could find a bevy of dissertations on the subject.
"What am I doing hanging round?"