The
database parameter JOIN_SEARCH_LEVEL determines the algorithm for the join sequence search. The level specified here determines how many resources and how much time the join sequence search takes.JOIN_MAXTAB_LEVEL4 is set to 16.
JOIN_MAXTAB_LEVEL9 is set to 4.
JOIN_SEARCH_LEVEL is set to 0.
5 tables are used for a join.
Join sequence search level 4 (transformer algorithm) is used for this join because the database parameter JOIN_MAXTAB_LEVEL9<5<=JOIN_MAXTAB_LEVEL4 is most appropriate.