Compression algorithm for posting lists

[Vishwas Jain]

Hello ,

          We are trying to implement better compression techniques in
lucene54 codec of Apache Lucene. Currently there is no such compression for
posting lists in lucene54 codec but LZ4 compression technique is used for
stored fields. Does anyone know why there is no compression technique for
postings lists? and what are the possible compression that would benefit if
implemented?

Thanks