Gaia will produce about 20 Terabytes of raw telemetry data that, after treatment and reduction, will generate a database of the order of 1 Peta byte. Contrary to other PI-based missions, Gaia data is required to reside in a database in its entirety, due to the complex interaction of the algorithms that will operate on the data to derive distances, proper motions astrophysical properties and create the final three-dimensional model of the Galaxy.To estimate the processing power and complexity required to build and manage such a database the European Space Agency issued the Gaia Data Access and Analysis Study (GDAAS) contract. This ongoing study is focusing on several important development issues. On the one hand, it aims to collect a relatively complete set of algorithms required to process Gaia Data and obtain from them estimates on CPU power, memory and archive size for the whole mission. On the other hand, it also aims to identify the most appropriate database management system technology that will not only be reliable, but will last beyond the 5-year lifetime of the mission.

An overview of GDAAS and its current results is presented.