In this lecture, I will first present the Swiss National Cohort, a linkage of administrative data at the national level that presents many similarities with the work done in the Institute of Cartography and Statistics of Andalusia. We will then go on to discuss the importance of these data, especially how we can use them to highlight and better understand the evolution of mortality in old age, as well as differential mortality by gender, social status and citizenship. Methods of data mining will be illustrated. Finally, we will consider, the spatial dimension. We will take as a first example the impact of the environment on the differences between Swiss nationals and foreigners, and as a second, the response of old age mortality to heatwaves.