Sequential retrieval of B-trees and a file structure with a dense B-tree index

A simple fast method is given for sequentially retrieving all the records in a B-tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B-tree is used as its dense index. It is easy to insert, delete or search a record, and it is also convenient to retrieve records in the sequential order of the keys. The merits and efficiencies of these methods or structures are discussed in detail.