1Z0-071 Data Definition Language (DDL) 3

Question 1

What does DESCRIBE (or DESC) command show for a table in Oracle SQL*Plus?

Accepted Answer

Column names, data types, and NULL/NOT NULL constraints

Answer

Row count and table size

Answer

All indexes on the table

Answer

The CREATE TABLE statement used to build the table

Question 2

Which view can you query to see all tables owned by the current user in Oracle?

Accepted Answer

USER_TABLES

Answer

DBA_TABLES

Answer

ALL_TABLES

Answer

V$TABLES

Question 3

What happens to dependent objects like views when you DROP a table in Oracle?

Accepted Answer

They become invalid but are not dropped

Answer

They are also dropped automatically

Answer

They continue to work because Oracle caches the data

Answer

Oracle raises an error and prevents the DROP

Question 4

Which DDL command is used to remove a column from an existing table?

Accepted Answer

ALTER TABLE ... DROP COLUMN

Answer

DELETE COLUMN

Answer

REMOVE COLUMN

Answer

MODIFY TABLE ... REMOVE COLUMN

Question 5

What does the ON DELETE CASCADE option on a FOREIGN KEY do?

Accepted Answer

Automatically deletes child rows when the parent row is deleted

Answer

Prevents deletion of parent rows that have child rows

Answer

Sets child foreign key values to NULL when the parent is deleted

Answer

Raises an error when a parent row deletion is attempted

Question 6

Which Oracle data type stores large amounts of character data beyond 4000 bytes?

Accepted Answer

CLOB

Answer

VARCHAR2

Answer

LONG

Answer

TEXT