B-Treaps: A Uniquely Represented Alternative to B-Trees

We present the first uniquely represented data structure for an external memory model of computation, a B-tree analogue called a B-treap. Uniquely represented data structures represent each logical state with a unique machine state. Such data structures are strongly history-independent; they reveal no information about the historical sequence of operations that led to the current logical state. For example, a uniquely represented file-system would support the deletion of a file in a way that, in a strong information-theoretic sense, provably removes all evidence that the file ever existed. Like the B-tree, the B-treap has depth O(logB n), uses linear space with high probability, where B is the block transfer size of the external memory, and supports efficient one-dimensional range queries.

• Type: Conference
• Year: 2009
• Where: ICALP
• Authors: Daniel Golovin
• Keywords: B-tree Analogue, Current Logical State, ICALP 2009, Such Data Structures, Theoretical Computer Science