Creative Commons: There are various versions of licensing through Creative Commons ranging from allowing sharing and derivatives commercially and non-commercially with attribution, to only non-commercial sharing with attribution and without derivatives. More details can be found here: http://creativecommons.org/licenses/
Italian Open Data License 2.0: This is derived from the Creative Commons license for Italy, and allows users the ability to share, modify, and use the database, while also requiring specifications such as explicit mentioning of the data source and the name of the data holder. More details can be found here (in Italian): http://www.formez.it/iodl/
Consult your legal team about the best licensing option to use for your data.