Question 2 :

What are row and column store indexes, explain ?

Row store indexes are used in OLTP tables in DB, where the indexes are created on transactional tables and the indexes are stored as pointers in RAM like rows.

Column store indexes are used in OLAP tables In data warehouse, where the indexes are created on analytical / non transactional tables.

Question 3 :
SSIS for loading data into fact / dim table

Data flow task   ------------------------------------------------------ >      Flat file source
       |     ( precedence constraint)                                                       |
Execute sql  task                                                                         Data conversion
                                                                                                           |
                                                                                                      Oledb source