Analysis of Query Optimizers

A query optimizer translates a query into a sequence of physical operators that can be directly carried out by the query execution engine.The goal of query optimization is to derive an efficient execution plan in terms of relevant performance measures, such as memory usage and query response time 
The query optimizer attempts to determine the most efficient way to execute a given query by considering the possible query plans. Importance: The goal of query optimization is to reduce the system resources required to fulfill a query, and ultimately provide the user with the correct result set faster. This is a feature of many relational database management systems and other databases such as graph databases.