What the difference between the b-tree and bitmap index structures

Chapter 6 Syntax Summary

The following table summarizes the syntax you have learned in this chapter. You can use the table

Create a

CREATE SEQUENCE sequencename

generate a series

[START WITH value]

INCREMENT BY 1

NOCACHE NOCYCLE;

[{MINVALUE value \|

NOMINVALUE}]

[{CYCLE \| NOCYCLE}]

[{ORDER \| NOORDER}]

NOMAXVALUE}]

[{MINVALUE value \|

NOMINVALUE}]

[{CYCLE \| NOCYCLE}]

[{ORDER \| NOORDER}]


Drop a sequence


Create a B-tree	CREATE INDEX indexname	CREATE INDEX

		ON customers(lastname);
Create a bitmap	CREATE BITMAP INDEX indexname	CREATE BITMAP INDEX
		customers_region_idx

Create a	CREATE INDEX indexname
function-based
		ON books(retail-cost);
Create an index	CREATE TABLE tablename
organized table
		title VARCHAR2(30) )
	ORGANIZATION INDEX;

	Command Syntax	Example

	RENAME TO newindexname;	books_profit_idx

RENAME TO


Drop an index			207

Create a
synonym

CREATE PUBLIC SYNONYM

synonymname

Drop a synonym

DROP PUBLIC SYNONYM

synonymname;

Displays objects accessible by the user

DBA_

Displays all objects in the database

Review Questions

1. 2. 3.

4. When is an index appropriate for a table?

5. What is the difference between the B-tree and bitmap index structures?

10. What is the purpose of a synonym?

Additional Database Objects