12. How many types of files can be avallable in SQL Server database and what is the recommended file name extension of each type of files? * 13. What is the major difference between primary data file and secondary data flies? Please research." 14. We have a system file group and a user file groups (optional) in SQL. Servec- What is the name of the system file group in any given database? * 15. It is possible to add Transaction Log file in a file group * True False 16. Why it is not advised to add additional Transaction fog file in a database? = 17. What is the maximum number of databases that can be created in SQL. Server instance? PYI. As per my experience, I baven't seen a sel Seryer Instance hosting more than 60 . databaves and the majonty of the Instances I was exposed so far have less than 20