Chess Skills had an interesting blog post concerning databases and their use back in March of 2011.
"Ever since the dawn of civilization, humans have sought help in games of chess that did not conclude in a single sitting. Such help takes many forms. Sometimes the help is actively encouraged. Other times it is forbidden.
When I was young, top level chess tournaments and world championship matches were characterized by adjournments. After many hours of play, a competitor would seal a move, eat a small meal, and go to sleep. While he slept, teams of seconds would labor through the night, analyzing the likely continuations. After a night of sleep and a hearty breakfast, the player would spend the morning with his seconds learning the results of overnight research. He returned to the game fully prepared for the next stages." ...READ MORE