Abstract—In distributed database system, the distributed
deposition and redundancy data brought convenient to fault
recovery, but they make distributed query processing more
complicated at the same time. Query optimization and processing
is one of the key technologies in distributed database system. It
generally uses semi-join operation to improve the time response
performance of query and reduce communication cost. This
paper briefly described the corresponding concepts and
characteristics of distributed database system, summarized the
goals of distributed database query optimization, and analyzed
the query optimization process based on semi-join operation
combined with the practical application. In addition, it
introduced a classical algorithm which is used for multiple
connection and query optimization based on the semi-join query
optimization, the SDD-1 algorithm.
Keywords-distributed database; semi-join operation; query
optimization