a) Assume that XYZ Stores is open for customers for business operations from 8:00am to 06:00pm. XYZ Stores has a database application to carry out the business operations. Database backup is essential to protect the data loss. As a Database Administrator working for XYZ stores, answer the following: Differentiate the two types of backup methods (hot/cold) and justify your choice of backup type for ABC Stores.

b) If we assume that the Database Administrator is never interested in running his or her own queries, does the DBA still need to understand query optimization? Why?

Please write your answer correctly and in details.