Fig. 6
From: Bitpacking techniques for indexing genomes: I. Hash tables
Results for retrieval of offset array values. Space and time usage for retrieving offset array values under various compression schemes. Offsets are obtained from 15-mer hash tables for the fly (dm5), chicken (gg4), and human (hg19) genomes. Graphs show the retrieval time in nanoseconds per query as a function of the space required in bytes for each format. a Retrieval results for a single value. b Retrieval results for two adjacent values. Methods tested: storage as 32-bit integers (Int vector), or compressed using Elias gamma coding (Gamma), Elias delta (Delta), Fibonacci, BP64-vertical format, or the BP64-columnar and BP32-columnar schemes introduced here. For retrieving two adjacent values using vectorized bitpacking formats, results are shown for both two-pass (slower) and one-pass (faster) implementations