The paper presents an overview of the problems astronomical data centers are facing today.

When one organizes a colloquium, one can do some fairly outrageous things, like putting ones own contribution first . However as an excuse for such a procedure, I shall say that I want really not to discuss that much what the C.D.S. itself does, but what problems we have been confronted with, specially those which came up since the last Strasbourg colloquium, or which got more complicated to handle.