Issue No.01 - January (1989 vol.15)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/32.21723
<p>The problem of optimizing joins between two fragmented relations on a broadcast local network is analyzed. Data redundancy is considered. Semantic information associated with fragments are used to eliminate necessary processing. More than one physical copies of a fragment is allowed to be used in a strategy to achieve more parallelism. Join-analysis graphs are introduced to represent joins on two fragmented relations. The problem of optimizing a join is mapped into an equivalent problem of finding a minimum-weight vertex cover for the corresponding join-analysis graph. This problem is proved to be NP-hard. A four-phase approach for processing joins is proposed.</p>
NP hardness; fragmented database systems; broadcast local network; relations; redundancy; parallelism; minimum-weight vertex cover; join-analysis graph; concurrency control; distributed databases; local area networks; relational databases.
J.S.J. Chen, V.O.K. Li, "Optimizing Joins in Fragmented Database Systems on a Broadcast Local Network", IEEE Transactions on Software Engineering, vol.15, no. 1, pp. 26-38, January 1989, doi:10.1109/32.21723