Subqueries can potentially be connected to the main query via multiple edges in several ways. Proximity, however, requires that a subquery can only be connected to the main query via a single edge. Figure 6.26 shows two queries that cannot currently be executed in Proximity.

Proximity cannot execute queries that have multiple boundary edges connecting the subquery to a single boundary vertex, or that have multiple boundary edges connecting the subquery to more than one boundary vertex. Queries can contain more than one subquery as long as each subquery has only a single boundary edge.