JOIN VIA RANGE OF MULTIPLE KEY COLUMNS 
JOIN VIA RANGE OF MULTIPLE KEY COLUMNS is a search strategy of the SQL optimizer.
When Can the System Use This Strategy?
The database system can use this search strategy if the join columns can be combined into the initial part of the key of the new table, which consists of multiple columns.
How Does the System Access the Data?
The database system accesses the table rows of the new table sequentially within the key range.