How fast can reads be thou? Even if skipping along a fixed offset, reading 4 byte identifiers to filter out location updates for vehicles, that's still a seque

How fast can reads be thou? Even if skipping along a fixed offset, reading 4 byte identifiers to filter out location updates for vehicles, that's still a sequential scan of a massive file. Wouldn't this read issue become a choking point to a degree that would make growth a curse? Then you get into weird architectures that exist solely to facilitate predigested reads?