Used memory in HANA - less/more/these same?

Hi,

I've question for you guys. I've database in DB2 (50GB) which data I import using Data Services to HANA, I change table type to column type. And in HANA I still have 50GB database. Why does it happen? I know that my database in HANA will use less used memory than in another "row" database. It's correct?

Thanks for answer.

Regards,

Pawel