Constrains the join algorithm choices available to the optimizer under certain circumstances.
UNSIGNED INT1 – 1,000,000
2500
Can be set temporary, for a user, or for the PUBLIC group. Takes effect immediately.
Specifies the minimum percentage of rows that must remain after all simple local predicates (expressed in parts-per-million) before the optimizer considers 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.
This option affects the optimizer only when the target table is very large. Under normal circumstances, you should not need to change this option.
