title: Robust relative compression of genomes with random access.
abstract: BACKGROUND
  Storing, transferring and maintaining genomic databases becomes a major challenge because of the rapid technology progress in DNA sequencing and correspondingly growing pace at which the sequencing data are being produced. Efficient compression, with support for extraction of arbitrary snippets of any sequence, is the key to maintaining those huge amounts of data.
  
  
  RESULTS
  We present an LZ77-style compression scheme for relative compression of multiple genomes of the same species. While the solution bears similarity to known algorithms, it offers significantly higher compression ratios at compression speed over an order of magnitude greater. In particular, 69 differentially encoded human genomes are compressed over 400 times at fast compression, or even 1000 times at slower compression (the reference genome itself needs much more space). Adding fast random access to text snippets decreases the ratio to ~300.
  
  
  BACKGROUND
  GDC is available at http://sun.aei.polsl.pl/gdc.
  
  
  BACKGROUND
  sebastian.deorowicz@polsl.pl.
  
  
  BACKGROUND
  Supplementary data are available at Bioinformatics online.
authors: Institute of Informatics, Silesian University of Technology, 44-100 Gliwice, Poland. sebastian.deorowicz@polsl.pl
authors: Sebastian
authors: S
authors: Deorowicz
authors: Szymon
authors: S
authors: Grabowski
mesh_terms: D000465:Algorithms; D044962:Data Compression; D030561:Databases, Nucleic Acid; D015894:Genome, Human; D023281:Genomics / Q000379:methods*; D006801:Humans; D017422:Sequence Analysis, DNA