On query optimization in relational databases

Abstract

Query Optimization is an important process in Relational databases. With the current load on databases increasing, the need to optimize queries in batches is a promising way out. Studies have shown that sharing among common sub-expressions can as well be beyond the optimal plans of the constituent queries. But challenges of excessively large sample space, buffer management, establishment of optimal order of optimization, and identification of disjoint queries remain in place. In this dissertation, We propose how We can efficiently establish the extent of inter-query shareability and exploit it so as to compute common sub-expressions once and share the output among the queries. We also propose the optimal order of optimization so that the sharing is done in a more cost saving and time conserving manner.