11. Heuristics for query optimization include: (a) performing selection operations as early as possible (b) performing projections early (c) restricting multiple join expressions to simple forms such as left-deep trees (d) a and b (e) all of the above 12. If you can build an index that supports index-only execution plans, is there any reason not to? (a) The queries for which index-only plans would be available are rare. (b) The index would include almost all fields in the table itself. (c) The expected cost of keeping the index updated outweights the savings in query processing. (d) All of the above. (e) None of the above-I would always support index-only execution plans if possible. 13. In SQL, users get privileges (a) only from the database administrator (b) from users with the same privileges and GRANT OPTION privilege (c) by means of a GRANT statement (d) a and c (e) b and c 14. Which of the following is not true about granted privileges in SQL? (a) If user A grants a privilege to user B and user A subsequently loses that privilege, user B may still have that privilege. (b) Privileges can be granted to users before the users are known to the DBMS. (c) A user can be granted a privilege without giving that user authorization to grant that privilege to others. (d) If privileges are revoked from one user, similar privileges may be automatically revoked from other users as well. 15. What does ACID stand for in the context of DBMS transactions? (a) Atomicity, Consistency, Isolation, and Durability (b) Analysis Console for Intrusion Databases (c) Atomicity, Consistency, Isolation, and Data (d) Automatic Classification and Interpretation of Data (e) Advanced Computing Information Database