* Population / Hamming weight
* Find first set (ffs) or Find first one
* Inversion
**研究论文：
# Matthias Vallentin, Vern Paxson, and Robin Sommer. "VAST: a unified platform for interactive network forensics." NSDI 2016.
# Gonzalo Navarro and Eliana Providel. “Fast, Small, Simple Rank/Select on Bitmaps.” SEA 2013.
===位图压缩===
* COMPAX (COMPressed Adaptive indeX )
** 研究论文
[1] Antoshekov G. Byte-aligned bitmap compression. Proc of the Conf on Data Compression. Piscataway, NJ: IEEE, 1994: 363- 098, 1994.
[2] Wu, Kesheng, Ekow J. Otoo, and Arie Shoshani. "Compressing bitmap indexes for faster search operations." In Scientific and Statistical Database Management, 2002. Proceedings. 14th International Conference on, pp. 99-108. IEEE, 2002.
[3] Wu, K., Otoo, E. J., and Shoshani, A. Optimizing bitmap indices with efficient compression. ACM Transactions on Database Systems (TODS), 31(1), 1-38, 2006.
[4] Stabno, Michał, and Robert Wrembel. "RLH: Bitmap compression technique based on run-length and Huffman encoding." Information Systems 34, no. 4, pp.400-414, 2009.
[5] F. Fusco, M. P. Stoecklin, and M. Vlachos, “Net-fli: on-the-fly compression, archiving and indexing of streaming network traffic,” Proceedings of the VLDB Endowment, vol. 3, no. 1-2, pp. 1382–1393, 2010.
[6] F. Deli`ege, T. B. Pedersen. Position list word aligned hybrid: optimizing space and performance for compressed bitmaps. In Proceeding of the 13th International Conference on Extending Database Technology, 2010.
[7] F. Corrales, D. Chiu, and J. Sawin, “Variable Length Compression for Bitmap Indexes,” DEXA’11, Springer-Verlag, pp.381-395, 2011.
[8] D. Lemire et al., “Sorting improves word-aligned bitmap indexes,” Data & Knowledge Engineering, 69(1), pp.3-28, 2010.
[9] S. J. van Schaik et al., “A memory efficient reachability data structure through bit vector compression,” SIGMOD, pp.913-924, 2011.
[10] S. Chambi, D. Lemire, O. Kaser, and R. Godin, “Better bitmap performance with roaring bitmaps,” Software: Practice and Experience, 2015.
[11] A. Schmidt, D. Kimmig, and M. Beine, “DFWAH: A Proposal of a New Compression Scheme of Medium-Sparse Bitmaps,” in the Third International Conference on Advances in Databases, Knowledge, and Data Applications (DBKDA 2011), pp. 192-195.
[12] R. Slechta, J. Sawin, B. McCamish, D. Chiu and G. Canahuate, A tunable compression framework for bitmap indices, In Data Engineering (ICDE’ 2014), pp. 484-495. IEEE.
**研究专利
[1] BBC, Byte aligned data compression, DEC/Oracle, http://www.google.com/patents/US5363098.
[2] WAH, Word aligned bitmap compression method, data structure, and apparatus, UC Berkeley, http://www.google.com/patents/US6831575.
[3] COMPAX, Network analysis, IBM, http://www.google.com/patents/US20120054160.
[4] PLWAH, Algorhyme, http://www.google.com/patents/US9236881.
== 混合结构（Hybrid） ==