International Journal of Information Studies Ibrahim Jaluta 5 3 2013 In this paper, we present adaptive concurrency-control protocol, adaptive replica-management protocol, and Blink- tree index algorithms for page-server database management systems in which the physical database is organized as a sparse B-link-tree. In these algorithms, a transaction T at client A can update a record r in a U-locked data page (B-link tree leaf-page) P cached at A, while transactions at other clients can simultaneously cache P and fetch available records other than r in P. This would not be possible if T should X-lock P in order to update it (as in the standard concurrency-control protocols). Hence, the degree of concurrency in the page-server system will be increased.