Packed-Memory Array as described in [1, 2, 3, 4].
[1] Michael A. Bender, Erik D. Demaine, and Martin Farach-Colton. Cache-oblivious B-trees. In Proceedings of the 41st Annual Symposium on Foundations of Computer Science (FOCS '00), pages 399--409, Redondo Beach, California, USA, November 2000. IEEE Computer Society.
[2] Michael A. Bender, Erik D. Demaine, and Martin Farach-Colton. Cache-oblivious B-trees. SIAM Journal on Computing, 35(2):341--358, 2005.
[3] Michael A. Bender and Haodong Hu. An adaptive packed-memory array. In Proceedings of the 25th ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems (PODS '06), pages 20--29, Chicago, Illinois, USA, June 2006. ACM.
[4] Michael A. Bender and Haodong Hu. An adaptive packed-memory array. ACM Trans. Database Syst., 32(4), November 2007.