Controls selectivity of which conditions the optimizer takes into account to calculate cardinality of a partial join when it searches for the best execution plan Meaning: 1 - use selectivity of index backed range conditions to calculate the cardinality of a partial join if the last joined table is accessed by full table scan or an index scan, 2 - use selectivity of index backed range conditions to calculate the cardinality of a partial join in any case, 3 - additionally always use selectivity of range conditions that are not backed by any index to calculate the cardinality of a partial join, 4 - use histograms to calculate selectivity of range conditions that are not backed by any index to calculate the cardinality of a partial join.5 - additionally use selectivity of certain non-range predicates calculated on record samples