Large databases on the GRID

In this talk, we address some general aspects of massive data access in the GRID environment, considering them from the point of view of some High Energy Physics experiences in large scale computing. These topics, despite of the angle from which we can consider them, are closely related to the general problem of accessing data in a massively distributed environment, where both the computing elements and the storage elements can be in different sites. Efficiently running such data-intensive applications can be very challenging in a single site, depending on the scale of the computations, running them in a worldwide distributed environment with chaotic user-related access patterns needs a design which avoids all the pitfalls which could harm its efficiency at a major degree.