Column stores generally compress the data better than row stores. Some xml systems like XMill[1] use column representations behind the scenes for this reason.

Column stores generally compress the data better than row stores. Some xml systems like XMill[1] use column representations behind the scenes for this reason. [1] - http://www.liefke.com/hartmut/xmill/xmill.html http://www.liefke.com/hartmut/xmill/xmill.html