What are optimizer hints, and how are they used?

 What are some general guidelines for creating and using indexes?

 Most query optimization techniques are designed to make the optimizer’s work easier. What factors should you keep in mind if you intend to write conditional expressions in SQL code?

  What recommendations would you make for managing the data files in a DBMS with many tables and indexes?

  What does RAID stand for, and what are some commonly used RAID levels?