You might want to check the M_SQL_PLAN_CACHE view.
There are some older presentations of mine still floating around here on SCN that could give you a easy start into this
Beyond that, you should
- check the documentation (there's a guide for performance tuning),
- if possible check the SAP HANA FAQ SAP notes and KBA's (just search for "FAQ" on component HAN* - every single one of them is worth the time to read it) and
- finally you might as well decide to go and buy my book
Book Announcement: SAP HANA Administration.
- Lars