range-hash partitioning range-list composite partitioning range-list partitioning ranges conditions dates eliminating gaps partitions references windowing analytic functions RANK analytic function RANK function ranking analytic functions DENSE_RANK overview RANK ROW_NUMBER RATIO_ records, listing in hierarchical order recursive relationships, traversing REFERENCE clause references cells models ranges values (PREVIOUS function) REGEXP functions REGEXP_INSTR function REGEXP_LIKE function 2nd 3rd REGEXP_REPLACE function 2nd REGEXP_SUBSTR function 2nd 3rd regions, joining registration of schemas regular expressions backreferences collation elements equivalence classes functions named character classes Perl usage syntax relational tables, moving data to relationships collection types creating nested tables unnesting variable arrays correlated subqueries evaluation recursive, traversing tables repeating sequences, matching replace_string reporting analytic functions RATIO_TO_REPORT report partitions representation of GROUP BY columns RESTRICT_REFERENCES pragma restrictions FOR loops hierarchical queries set operations WITH CHECK OPTION result sets Cartesian products finding what data is not in database GROUPING_ID function refining, WHERE clause set operations, column names transforming CASE expression DECODE function WHERE clause, conditions retrieving data customer table SELECT statement return_option RIGHT outer joins 2nd righthand side of rules, range references ROLLUP keyword group operations partial rollups root nodes listing XML root, hierarchical queries ROUND function 2nd rounding dates ROWID pseudocolumn ROWNUM, GROUP BY clause and rows aggregate functions modification of returning WITH CHECK OPTION ROWS BETWEEN clause, unbounded windows RR (year) indicator RRRR (year) indicator RTRIM function, dates rules iterative models model queries RULES clause ITERATE subclause RULES keyword