A restructuring method for the concurrent B+-tree based on semantic consistency

As the B-tree index could be a performance bottleneck in database systems, concurrent B-tree algorithms have been intensively studied to improve concurrency of B-tree accesses in the literature. We propose a new concurrent B⁺-tree algorithm for high concurrency and an efficient tree restructuring method. Because the proposed method of tree restructuring always preserves a semantic consistency of the B⁺ -tree, a key searcher need not require any lock for a range search as well as a single-key search. To maintain correctly the link fields constructed at the leaf level, we make each leaf node contain two key-range indicators, and develop a tree restructuring method using these key-range indicators