Ad-hoc graphs, i.e. graphs that are simply creatable from the admin UI are not meant for storing anything of serious size. For that you really should implement your own graph provider what's not really complex. The upcoming release of Associativy will feature much better ad-hoc graph support (remember: automatically generated tag graphs are ad-hoc graphs too!) but the migration is not very easy. To keep things simple please don't create more than one ad-hoc graph for now. Migration will only be supported for one ad-hoc graph. If you have more than one please contact us and we'll help!