sql/nosql approach for dynamic dashboard design

I need to create a SQL/ NoSQL design for highly dynamic dashboard that contains multiple customizable widgets. i.e., a dashboard for each user, mutiple widgets there, one can add more widgets in dashboard, one can change the sequencing of widgets and all.

I had created a RDBMS approach for this but then m thinking if this could not perform well, is there a NO SQL approach that perfom better like xML formal.

please guide or any standard XML template for reference