Algorithm to compute partitions of a graph in N cliques does anyone know of an efficient algorithm to compute the partition of a graph in N cliques?

Notice that N is the number of the cliques and not the size of them.

I have heard of the 2 cliques problem, but I'm interested in the more general version.
This problem is known as clique cover and it's NP-complete. In other words, no efficient algorithm is known.