An Empirical Evaluation of LIKE Operator in Oracle

In database systems, user makes query and that query will be responded by the DBMS. Generally, there are a variety of methods for computing the response of the given query. It is the responsibility of the query processor to transform the query as entered by the user into an equivalent query that can be computed more efficiently. Query optimization is the process to find a good strategy or best query evaluation plan for processing a query. In the today’s competitive environment, query optimization is one of the important criteria based on which one can compare the available commercial RDBMSs. The objective of this study is to discuss about techniques used by the Oracle for optimizing the queries and to present a comparative study of the various costs involve to execute the LIKE Operator based queries. This comparative study is based on empirical study done on Oracle 8i, Oracle 9i and Oracle 10g.