Not the same. If, for example, you use MARA, the first one is identical to
SELECT * FROM mara INTO work_area
WHERE field = field
ORDER BY matnr.
ENDSELECT.
The second one has no defined order. I can't see why this would be any different in HANA. The underlying mechanism may be different. The performance may vary according to database.
If you get different results according to your database, that would make a mockery of open SQL.