Understanding Wide-Column Stores
  To understand the concept  more clearly, let’s start with an example of  Relational database :      Customers    Id   Product   FN   Date   Country    1   Dell   Harry   17/04/2018   India    2   Dell   Harry   17/04/2018   India    3   Apple   Ron   17/04/2018   India    4   Sony   Ron   17/04/2018   South Africa    5   Sony   Hermione   17/04/2018   South Africa        When we convert this to a  Column Store , this is how it looks like:     FN   LN   Product   Date   Country    Id   Value   Id   Value   Id   Value   Id   Value   Id   Value    1-2   Harry   1-2   Potter   1-2   Dell   1-5   17/04/2018   1-3   India    3-4   Ron   3-4   Weasley   3   Apple   4-5   South Africa    5   Hermione   5   Granger   4-5   Sony       Now a  Wide Column store  will Group the columns which are accessed frequently together into one , like      Id   Name    1-2   FN   Harry    LN   Potter    3-4   FN   Ron    LN   Weasley    5   FN   Hermione    LN   Granger       Some key...