Incquery is a Xtext dsl that allows you to make request on an EMF Model. It’s also incremental because it reacts to EMF notifications.
It seems to be very fast and applicable to huge models.
Incquery have also some annotation allowing you to specify how to see your results: for example which query result must represent an edge or a node, resulting a graph visualization (with zest, yfiles, jface tree).
Incquery can also be mixed with XCore to define derived relations (incquery queries) that are notification aware. for example, you can define an “author with books” derived feature (Aldous Huxley [“Le meilleur des mondes”]), and change then EMF model when the end-user changes the book title.