Simple, robust and highly concurrent b-trees with node deletion

Why might B-tree concurrency control still be interesting? For two reasons: (i) currently exploited "real world" approaches are complicated; (ii) simpler proposals are not used because they are not sufficiently robust. In the "real world", systems need to deal robustly with node deletion, and this is an important reason why the currently exploited techniques are complicated. In our effort to simplify the world of robust and highly concurrent B-tree methods, we focus on exactly where B-tree concurrency control needs information about node deletes, and describe mechanisms that provide that information. We exploit the B/sup link/ -tree property of being "well-formed" even when index term posting for a node split has not been completed to greatly simplify our algorithms. Our goal is to describe a very simple but nonetheless robust method.