  Several algorithms have been developed over the years to perform join
operation which is executed frequently and affects the efficiency of the
database system. Some of these efforts prove that join performance mainly
depends on the sequences of execution of relations in addition to the hardware
architecture. In this paper, we present a method that processes a many-to-many
multi join operation by using a non-recursive reverse polish notation tree for
sort-merge join. Precisely, this paper sheds more light on main memory join
operation of two types of sort-merge join sequences: sequential join sequences
(linear tree) and general join sequences (wide bushy tree, also known as
composite inner) and also tests their performance and functionality. We will
also provide the algorithm of the proposed system that shows the implementation
steps.
