Efficient Rebalancing of Chromatic Search Trees

In PODS'91, Nurmi and Soisalon-Soininen presented a new type of binary search tree for databases, which they call a chromatic tree. The aim is to improve runtime performance by allowing a greater degree of concurrency, which, in turn, is obtained by uncoupling updating from rebalancing. This also allows rebalancing to be postponed completely or partially until after peak working hours. The advantages of the proposal of Nurmi and Soisalon-Soininen are quite significant, but there are definite problems with it. First, they give no explicit upper bound on the complexity of their algorithm. Second, some of their rebalancing operations can be applied many more times than necessary. Third, some of their operations, when removing one problem, create another. We define a new set of rebalancing operations which we prove give rise to at most log2(N + 1) - 1 rebalancing operations per insertion and at most log2(N + 1) - 2 rebalancing operations per deletion, where N is the maximum size the ...

• Type: Conference
• Year: 1992
• Where: SWAT
• Authors: Joan Boyar, Kim S. Larsen
• Keywords: Algorithms, Binary Search Tree, Peak Working Hours, Rebalancing, SWAT 1992