Can you describe the purpose of an Oracle SQL execution plan?
While you are interviewing for a specific job that involves optimizing an Oracle database, you're likely to be asked questions about all the functions and components of the DBMS. Interviewers ask these types of questions to confirm that you have a complete understanding of the Oracle environment and can use all of the commands, variables, and other items within Oracle to tune and optimize the database. The interviewer may also ask you questions about related topics such as applications, storage, memory, and other components of a system that impact Oracle's performance.
It is virtually impossible to know every item, component, command, and issue impacting an Oracle database's performance. Interviewers know this and will not expect you to know everything. However, you are expected to know the most important things, the common issues you will encounter, and the commands used to execute common tasks required of an Oracle administrator. Reviewing these before the interview will help prepare you for the majority of questions you will be asked. It is perfectly acceptable to admit that you do not know an answer to an interviewer's question as long as you can describe how you would locate the information needed to perform the task they describe.
"The purpose of an oracle SQL execution plan is to create a road map of how Oracle DBAs execute SQL. This helps Oracle administrators structure the database, create the tables, and execute SQLs to provide the information and data needed by the users to perform their jobs."
