READ Free Dumps For Oracle- 1z0-007
| Question ID 7945 | What does the TRUNCATE statement do?
|
| Option A | Removes the table
|
| Option B | Removes all rows from a table
|
| Option C | Shortens the table to 10 rows
|
| Option D | Removes all columns from a table
|
| Option E | Removes foreign keys from a table
|
| Correct Answer | B |
Explanation Explanation/Reference: Explanation: Command TRUNCATE is used to remove all row data from the table, while leaving the definition of the table intact, including the definition of constraints and any associated database objects as indexes, constraints, and triggers on the table. Incorrect Answers A: Command TRUNCATE does not remove the table. DROP TABLE command does that. C: There is no command in Oracle to shortens the table to 10 rows: but you can do this with queries. D: This command does not remove all columns from a table. E: This command does not remove all foreign keys from a table. OCP Introduction to Oracle 9i: SQL Exam Guide, Jason Couchman, p. 225 Chapter 5: Creating Oracle Database Objects
| Question ID 7946 | You need to change the definition of an existing table. The COMMERCIALS table needs its DESCRIPTION column changed to hold varying length characters up to 2000 bytes. The column can currently hold 1000 bytes per value. The table contains 20000 rows. Which statement is valid?
|
| Option A | ALTER TABLE commercials MODIFY (description CHAR2(2000));
|
| Option B | ALTER TABLE commercials CHANGE (description CHAR2(2000));
|
| Option C | ALTER TABLE commercials CHANGE (description VARCHAR2 (2000));
|
| Option D | ALTER TABLE commercials MODIFY (description VARCHAR2 (2000));
|
| Option E | You cannot increase the size of a column if the table has rows.
|
| Correct Answer | D |
Explanation Explanation/Reference: Explanation: Incorrect Answers A: There is no CHAR2 datatype in Oracle. Also 200 symbols is not enough to store up to 2000 bytes. B: There is no CHAR2 datatype in Oracle. There is no ALTER TABLE table_name CHANGE command in Oracle. C: There is no ALTER TABLE table_name CHANGE command in Oracle. E: You can increase the size of a column if the table has rows. It can be done with ALTER TABLE table_name MODIFY column. OCP Introduction to Oracle 9i: SQL Exam Guide, Jason Couchman, p. 219-224 Chapter 5: Creating Oracle Database Objects