I also wonder if Athena does this with AWS. Parquet supports pushdown. But i would suspect, pushdown predicates would mean that the file storage unit has to have some logic to execute custom code, bringing back the code to the data. The promise of spark, once. It would be a huge win, definitly. Hmmm.
But opens up also a threat vector. And you have competing users running their predicates. So one has to think also about queues and pipelining and so on. But probably also solvable, just like on any multiuser system.
Interesting.