An operation to join a table to itself is called a(n): a) sufficient-join. b) inner join. c) outer join. d) self-join. 7. A type of query that is placed within a WHERE or HAVING clause of another query is called a: a) master query. b) subquery. c) superquery. d) multi-query. 8. SQL provides the technique, which involves placing an inner query within the WHERE or HA VING clause of an outer query. a) grouping b) joining c) subquery d) union 9. takes a value of true if a subquery returns an intermediate results table which contains one more rows. a) N b) HAVING c) EXISTS d) EXTENTS 10. EXISTS will take a value of if the subquery returns an intermediate results table which contains one or more rows. a) FALSE b) 1 (c) TRUE d) undefined 11. The clause is used to combine the output from multiple queries into a single result table a) INTERSECT b) DIVIDE c) COLLATE d) UNION 12. In order for two queries to be UNION-compatible, they must: a) both have the same number of lines in their SQL statements. b) both output same number of columns with compatible data types. c) both return at least one row. d) all of the above. 13. The UNION clause is used to: a) combine the output from multiple queries into a single result table. b) join two tables together to form one table. c) find all rows that do not match in two tables. d) none of the above. 14. All of the following are guidelines for better query design except: a) understand how indexes are used in query processing. b) use a lot of self-joins. c) write simple queries. d) retrieve on the data that you need. 15. What results would the following SQL statement produce (where dba tables is the system containing the metadata for other tables)? select owner, table_name from dba tables where table_name = 'CUSTOMER'; a) A listing of all customers in the customer table b) A listing of the owner of the customer table c) A listing of the owner of the customer table as well as customers d) An error message