ABSTRACT:

Multidimensional databases are starting to be employed in a wide selection of applications. To meet this fast-growing demand, the R-tree family is being applied to support fast access to multidimensional information, for that the R+-tree exhibits outstanding search performance. In order to support efficient concurrent access in multiuser environments, concurrency management mechanisms for multidimensional indexing have been proposed. However, these mechanisms can not be directly applied to the R+-tree as a result of an object in the R+-tree might be indexed in multiple leaves. This paper proposes a concurrency control protocol for R-tree variants with object clipping, particularly, Granular Locking for clipping indexing (GLIP). GLIP is the first concurrency control approach specifically designed for the R+-tree and its variants, and it supports economical concurrent operations with serializable isolation, consistency, and deadlock-free. Experimental tests on both real and artificial knowledge sets validated the effectiveness and efficiency of the proposed concurrent access framework.