If you need data to fill your brand new (graph) database, go ahead, there’s something to load:

“KONECT (the Koblenz Network Collection) is a project to collect large network datasets of all types in order to perform research in network science and related fields, collected by the Institute of Web Science and Technologies at the University of Koblenz–Landau. KONECT contains over a hundred network datasets of various types, including directed, undirected, bipartite, weighted, unweighted, signed and rating networks. The networks of KONECT are collected from many diverse areas such as social networks, hyperlink networks, authorship networks, physical networks, interaction networks and communication networks. The KONECT project has developed network analysis tools which are used to compute network statistics, to draw plots and to implement various link prediction algorithms. The result of these analyses are presented on these pages. Whenever we are allowed to do so, we provide a download of the networks.”

KONECT currently holds 157 networks, of which

36 are undirected, 51 are directed, 70 are bipartite, 68 are unweighted,

72 allow multiple edges, 6 have signed edges, 10 have ratings as edges, 1 allows multiple weighted edges, and 64 have edge arrival times.

Source 1: http://konect.uni-koblenz.de/