Column Store vs Row Store

E.g.: If you want to select country as JP and product is Alphathen traditional db with row store will read all the rows  one by one and reach our query what we want. but with column store it won't read all the rows in sequence manner instead it selects the particular column. by this way we will get our result faster with in less time.

Why data comes faster from RAM?

   Take an example if you play songs from your hard drive it takes less time instead of playing songs from DVD drive , external disks or pen drive, because it takes time to read from disk . If data present in RAM then we will access to reports within seconds by columnar hana db and calculations can be done on fly.