maintenance, WHERE clause match_parameter matching conditions math, dates addition overview subtraction MAX function MEASURES clause 2nd MEMBER OF operator membership conditions merge anti-joins merge semi-joins Merge statement methods, partitioning MINUS set operator 2nd comparing tables minutes date math representations of MODEL clause model queries elements of iterative reference models months date math first day, returning last day, returning MONTHS_BETWEEN function 2nd multilevel collections multiple collections, executing set operations multiple columns, conditions multiple summary levels multiple-condition evaluation 2nd multiple-row subqueries, errors MULTISET EXCEPT function MULTISET INTERSECT function MULTISET UNION DISTINCT function multitable inserts