Hi guomimi,
A bit more information (and some questions) in addition to jskinner-esristaff's reply.
GeoAnalytics supports points, lines, polygons and tables formats for big data file shares. There isn't a strict requirement for the headers, but the headers are used when you generate the manifest to try and automatically determine which fields represent geometry and/or time. So if you want to add a header, I would recommend a single row, name it with headings that makes sense, don't have a space in the header names, and if you have time or geometry fields name them time or geometry.
When you register the manifest GeoAnalytics will do a best guess to figure out the geometry field and format. If you have something a bit more complex, you may need to edit the manifest yourself.
What version of Enterprise are you using, and how are you line geometries stored in the CSV? WKT? something else?
Looking forward to seeing how that goes,
Sarah Ambrose
Product Engineer, GeoAnalytics