Markus Innerebner <markus.innerebner@inf.unibz.it> writes:
> The query plan says, that a sequential scan is performed on the edge table. I consider it strange that he is not
accessingon the (btree) index one the edge table.
This suggests that you have a datatype mismatch:
> " Hash Cond: ((e.target)::numeric = n.id)"
Your index is presumably on e.target, not e.target::numeric, so it's not
applicable. Try to make the join columns the same datatype.
regards, tom lane