PostgREST is a standalone web server that turns your PostgreSQL database directly into a RESTful API. The structural constraints and permissions in the database determine the API endpoints and operations.
Apache Sqoop(TM) is a tool designed for efficiently transferring bulk data between Apache Hadoop and structured datastores such as relational databases.
M. Thein, and M. Thwin. International Journal of Computer Science, Engineering and Information Technology (IJCSEIT), volume 2 of IFIP Advances in Information and Communication Technology, page 13-32. Springer, (December 2012)
J. Correia. Proceedings of the 10th International Conference on Conceptual Structures (ICCS 2002), volume 2393 of Lecture Notes in Computer Science, page 62-76. Springer, (2002)
G. Stumme, R. Wille, and U. Wille. Principles of Data Mining and Knowledge Discovery Proc. 2nd European Symposium on PKDD'98, volume 1510 of LNAI, page 450-458. Heidelberg, (1998)Part of hereth03conceptual.