Showing papers by "Jeffrey Scott Vitter published in 2018"
27 Mar 2018
TL;DR: A practical succinct external memory text index, called mKD-GBWT, that can represent a point using fewer bits and perform a query in a reduced region so as to improve the space usage and I/Os of GBWT in practice.
Abstract: Chien et al [1, 2] introduced the geometric Burrows-Wheeler transform (GBWT) as the first succinct text index for I/O-efficient pattern matching in external memory; it operates by transforming a text T into point set S in the two-dimensional plane In this paper we introduce a practical succinct external memory text index, called mKD-GBWT We partition S into ς2 subregions by partitioning the x-axis into ς intervals using the suffix ranges of characters of T and partitioning the y-axis into ς intervals using characters of T, where ς is the alphabet size of T In this way, we can represent a point using fewer bits and perform a query in a reduced region so as to improve the space usage and I/Os of GBWT in practice In addition, we plug a crit-bit tree into each node of string B-trees to represent variable-length strings stored Experimental results show that mKD-GBWT provides significant improvement in space usage compared with the state-of-the-art indexing techniques The source code is available online [3]