You have a large Parquet file and an API that has to return its contents, but responses have a size ceiling, so the caller pages through it. LIMIT/OFFSET is the obvious way to write that and it is the wrong one. I measured file_row_number against it: 2.53x faster on a file with 163 row groups. Speed is the boring half of the answer. OFFSET will also hand back the wrong rows without telling you.