Database options for push-down join optimizer tables [CR 368261]

New database options provide a lower bound, expressed in parts-per-million, for the tables into which the optimizer is willing to consider using push-down joins. These options only affect the optimizer when the target table is very large. Under normal circumstances, you should not need to change these options.

• MIN_SMPDJ_OR_HPDJ_FILTERED_PPM

  UNSIGNED INT Default: 2500

  Specifies the minimum percentage of rows that must remain after all simple local predicates (expressed in parts-per-million) before the optimizer will consider using either the hash push-down join (HPDJ) or sort-merge push-down join (SMPDJ) algorithms. The default is equivalent to a selectivity of 0.0025, or one quarter of one percent of the table.

• MIN_NLPDJ_FILTERED_PPM

  UNSIGNED INT Default: 2500

  Specifies the minimum percentage of rows remaining after all simple local predicates (expressed in parts-per-million) before the optimizer will consider using the nested-loop push-down join (NLPDJ) algorithm.