International Journal of Emerging Technology and Advanced Engineering (IJETAE)
In a relational database all information can be found in a series of tables. A query therefore consists of operations on tables for retrieving the data from tables. In this paper, the authors will introduce the reader to the basic concepts of query processing and query optimization in the relational database domain. How a database processes a query as well as some of the algorithms and rule-sets utilized to produce more efficient queries will also be presented. This is responsible for translating a user submitted query usually written in a non-procedural language in to an efficient query evaluation program that can be executed against database.