Compression

Next Thursday I'll cover the topic of index compression. Applying good compression techniques to an inverted index yields a number of performance benefits in practice. Index compression is covered by this chapter in the textbook, and I'll additionally use this deck to illustrate two integer compression techniques not mentioned in the textbook: Simple9 and PFOR-DELTA. This paper is very implementation-oriented, but its Related Work section gives a good summary of several families of compression algorithms, if you are interested.