1. A method, implemented at least partly by a device, for facilitating execution of a database query of a database, wherein the database query requires multiple sub-queries to be executed as multiple iterations such that a result of a first one of the sub-queries is needed to be determined in a first iteration of the iterations in order to determine a result of a second one of the sub-queries in a second iteration of the iterations to be performed after the first iteration, and wherein the method comprises: estimating a projected number of iterations required to execute the database query including the first and second iterations at least partly by determining the projected number of iterations at least partly based on the following: (i) an estimated number of all nodes in one or more recursion trees (I) that represent the organization of data involved in the database query, (ii) the number of nodes in the one or more recursion trees that originate at a seed (S) provided as input of the database query, and (iii) an estimated average of the outgoing edges of the nodes of the one or more recursion trees (Avg_outDegree); and determining at least one execution plan for executing one or more of the iterations, at least partly based on the projected number of iterations required to execute the database query.