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

DESC table_name displays each column's name, nullability, and data type in SQL*Plus and SQL Developer.

Question 2

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

Accepted Answer

USER_TABLES

Answer

USER_TABLES shows metadata about all tables owned by the currently logged-in Oracle user.

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

When a base table is dropped, views and synonyms that depend on it become INVALID but remain in the data dictionary.

Question 4

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

Accepted Answer

ALTER TABLE ... DROP COLUMN

Answer

ALTER TABLE ... DROP COLUMN removes a column and all its data from an existing table.

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

ON DELETE CASCADE automatically deletes all child rows in the referencing table when the parent row is deleted.

1Z0-071 - Oracle Database SQL Certified Associate Practice Test