In this paper we study the problem of supporting concurrent operations in B-trees and their variants. A survey of previous work is given and two basic types of solutions to this problem are identified. A new solution with a greater degree of concurrency is proposed. As solutions are surveyed or presented we identify useful techniques which have wider applicability. In particular, we introduce the technique of side-branching in our new solution.

In recent years B-trees have become a common data structure for representing large data dictionaries. In this paper we investigate the often ignored relationship between routing schemes and the permissible operations in leaf-search B-trees. We show that among the many commonly used routing schemes in the literature, some are cleaner than others, making them more attractive for leaf-search B-trees supporting concurrency.