Application for grocery shop

Question

Hi

Client needs to create an application that will run in their 3 to 4 Grocery stores (just like Big Bazar)

Please guide me the best approach for storing their data. I shall use SQL Server.

 

Should I use same centralized database for all their grocery stores and fetch the data according to their machine name (an identical object) or shall I use seperate database for each store.

 

I thought: 

If I use centralized database then it should be more difficult to take backup and restore the database and the database will also will bulky.

 

The most important thing that the admin should able to look all the data of all the stores.

 

Please suggest

 

Thank you