Ch. 3

Question 1

________ _____ _______ are commands used to create or modify database tables.

Answer 1

data definition language (DDL)

Question 2

A ________ is a defined, self-contained structure in Oracle 11g.

Answer 2

database object

Question 3

Database tables are also considered to be database _______.

Answer 3

objects

Question 4

What is the command that creates a new table in the database. The user names the columns and identifies the type of data to be stored?

Answer 4

CREATE TABLE

Question 5

What command creates a table from existing database tables, using the AS clause and subqueries?

Answer 5

CREATE TABLE . . . AS

Question 6

What command adds a column to a table?

Answer 6

ALTER TABLE . . . ADD

Question 7

What command changes a column size, datatype, or default value?

Answer 7

ALTER TABLE . . . MODIFY

Question 8

What command deletes one column from a table?

Answer 8

ALTER TABLE . . . DROP COLUMN

Question 9

What command marks a column for deletion at a later time?

Answer 9

ALTER TABLE . . . SET UNUSED
OR
SET UNUSED COLUMN

Question 10

What command completes the deletion of a column previously marked with SET UNUSED?

Answer 10

DROP UNSED COLUMNS

Question 11

What command changes a table name?

Answer 11

RENAME . . . TO

Question 12

What command deletes all table rows, but the table name and column structure remain?

Answer 12

TRUNCATE TABLE

Question 13

What command removes an entire table from the Oracle 11g database?

Answer 13

DROP TABLE

Question 14

What command permanently deletes a table in the recycle bin?

Answer 14

PURGE TABLE

Question 15

What command recovers a dropped table if PURGE option not used when table dropped?

Answer 15

FLASHBACK TABLE . . . TO BEFORE DROP

Question 16

The names of ________ and _______ can be up to 30 characters and must begin with a letter. These limitations apply only to a ______ or _______ name, not to data in a column.

Answer 16

table and column

Question 17

The names of tables and columns can’t contain any ______ spaces.

Answer 17

blank

Question 18

Numbers, the underscore symbol (_), and the number sign (#) are allowed in _____ and ______ names.

Answer 18

table and column

Question 19

Each table owned by a user should have a ______ table name, and the column names in each table should be _____.

Answer 19

unique

Question 20

What are Oracle 11g “reserved words”, and can’t be used for table or column names?

Answer 20

SELECT, DISTINCT, CHAR, and NUMBER

Question 21

What is the description of VARCHAR2(n)?

Answer 21

Variable-length Character data, and the n represents the column’s max length.

• Max is 4000 characters
• no default size for this datatype
• minimum value must be specified
• can contain letters, numbers or symbols

Question 22

What is the description of CHAR(n)?

Answer 22

Fixed-length character column, the n represents the column’s length.

• default size is 1
• max size is 2000
• can contain number, letters or symbols
• if fewer than (n) are entered, spaces are added to the right to force the data to reach a length of (n)

Question 23

What is the description of NUMBER(p, s)?

Answer 23

Numeric column. The p indicates Precision, the total number of digits to the left and right of the decimal position, to a maximum of 38 digits.
- the s, or Scale, indicates the number of positions to the right of the decimal.

Question 24

What is the description of DATE?

Answer 24

stores dates

Question 25

A ______ identifies the type of data Oracle 11g is expected to store in a column.

Answer 25

datatype

Question 26

A ________ _______ generates a value automatically based on other column values in the table.

Answer 26

Virtual Column

Question 27

A ________ can be included to indicate who “owns” the table.

Answer 27

Schema

Question 28

A _______ is a SELECT statement used in another SQL command.

Answer 28

Subquery