"When hiring QA managers, employers are looking for candidates with the technical background and management skills to assist the QA department at a high level. In an interview, be ready to answer typical testing questions as well as speak to your leadership experience and project management abilities. Come prepared to discuss how you would set quality standards, execute testing planning, and ensure that teams meet deadlines."
In a typical sql query, what would happen when there are no bind variables? What happens when you put bind variables, does it help the performance or not? If so, how?
While writing queries in SQL always prefer using the Binding Variables. Here's why: Everytime a query is executed, it is first checked into the Shared Pool to see whether the query was executed before or not. If yes, then its execution plan is used again to execute the new query. If no, Hard Parse is done by the database. The query is parsed, working out the various execution paths and coming up with an optimal access plan before it can be executed. Hard parsing is very CPU intensive, and involves obtaining latches on key shared memory areas. So, lets take an example: Collapse | Copy Code select * from table1 where salary = 2000 Now if the value 2000 changes everytime with input from user, the query will never be unique and will be hard parsed everytime, generating extra CPU burden. Solution: Binding Variables Example: Collapse | Copy Code select * from table1 where salary = :salary Now this makes the statement unique everytime and just the values change in it, reducing the Hard Parse overhead. Every reference to a PL/SQL variable is in fact a binding variable.