Extracting and interpreting data can be very valuable to an organization. Describe the importance of using sub queries in a database system. Provide at least two business case scenarios to support you

Extracting and interpreting data can be very valuable to an organization. Describe the importance of using sub queries in a database system. Provide at least two business case scenarios to support your response. 

A good IT professional is able to be versatile in SQL programming styles. Identify at least two possible advantages of utilizing PL / SQL instead of standard SQL Syntax. Explain whether either syntax provides enhanced code processing capabilities with examples.