Altering Oracle Indexes - Quiz

Each question is worth one point. Select the best answer or answers for each question.

1.	Which of the following is not a valid option for altering an index? Please select the best answer.
	A.	`DROP COLUMN`
	B.	`RENAME TO`
	C.	`REBUILD`
	D.	`COALESCE`

2.	Which of the following are benefits from rebuilding indexes? Please select all the correct answers.
	A.	Save disk space for the index
	B.	Resort the index
	C.	Change the order of columns in the index
	D.	Potentially improve I/O performance on the index

3.	What is the key difference between rebuilding and index and coalescing an index? Please select the best answer.
	A.	Coalescing an index saves more space.
	B.	Rebuilding an index causes the index to be put in sorted order, while coalescing an index does not sort the index values.
	C.	Rebuilding an index works on the whole index, while coalescing an index only affects the leaf blocks.
	D.	Rebuilding an index works on the whole index, while coalescing an index only affects the index nodes.