Query optimization is the task of improving the strategy for processing a
database query. Query processing refers to the range of activities involved in
extracting data from a database. A database query on relational databases
can be represented as a query tree, where the leaf nodes represent accesses
to relations. The intermediate nodes process and combine the data from their
input nodes using physical implementations of the relational operations of
projection, join etc. Usually the exploratory queries are loosely structured and
require only minimal user knowledge of the source network. Evaluating an
exploratory query usually involves the evaluation of many distributed queries.
As the number of such distributed queries can quickly become large, we attack
the optimization problem for exploratory queries by proposing several multiquery
optimization algorithms that compute a global evaluation plan while
minimizing the total communication cost, a key bottleneck in distributed
settings.