Oracle Constraints By Blue Blaze

20 Questions

Settings
Please wait...
Oracle Quizzes & Trivia

Questions and Answers
  • 1. 
    WHERE  clauses allows alias names.
    • A. 

      True

    • B. 

      False

  • 2. 
    _________  constraint is used to limit the value range that can be placed in a column.
  • 3. 
    Select the statement which is collectively known as TCL?
    • A. 

      Commit

    • B. 

      Savepoint

    • C. 

      Rollback

    • D. 

      Grant

  • 4. 
    Constraints are classified into _________ and __________ constraints.
    • A. 

      Column level

    • B. 

      Table level

    • C. 

      Row level

  • 5. 
    You can drop a column in a table with a simple ALTER TABLE DROP COLUMN statement, even if the column is referenced in a constraint.
    • A. 

      True

    • B. 

      False

  • 6. 
    All of a user's constraints can be viewed in the Oracle Data Dictionary view called: 
    • A. 

      USER_TABLES

    • B. 

      USER_CONSTRAINTS (*)

    • C. 

      CONSTRAINTS

    • D. 

      TABLE_CONSTRAINTS

  • 7. 
    What mechamisn does Oracle use in the background to enforce uniqueness in Primary and Unique key constraints? 
    • A. 

      Unique indexes are created in the background by Oracle when Primary and Unique constraints are created or enabled (*)

    • B. 

      Nothing extra is created when Primary Keys and Unique Keys are created

    • C. 

      Internal Pointers

    • D. 

      Ordered Lists

  • 8. 
    The command to 'switch off' a constraint is: 
    • A. 

      ALTER TABLE STOP CHECKING

    • B. 

      ALTER TABLE DISABLE CONSTRAINT (*)

    • C. 

      ALTER TABLE STOP CONSTRAINTS

    • D. 

      ALTER TABLE PAUSE CONSTRAINT

  • 9. 
    Once constraints have been created on a table you will have to live with them as they are unless you drop and re-create the table.
    • A. 

      True

    • B. 

      False

  • 10. 
    The SQL WHERE clause:
    • A. 

      limits the column data that are returned.

    • B. 

      Limits the row data are returned.

    • C. 

      Both A and B are correct.

    • D. 

      Neither A nor B are correct.

  • 11. 
     Which of the following is valid SQL for an Index?
    • A. 

      CREATE INDEX ID;

    • B. 

      CHANGE INDEX ID;

    • C. 

      ADD INDEX ID;

    • D. 

      REMOVE INDEX ID;

  • 12. 
    To remove duplicate rows from the results of an SQL SELECT statement, the ________ qualifier specified must be included.
    • A. 

      ONLY

    • B. 

      UNIQUE

    • C. 

      DISTINCT

    • D. 

      NULL

  • 13. 
    There is a possibility to create more  than one primary key on a single table
    • A. 

      True

    • B. 

      False

  • 14. 
    Check constraint can be used for self refential integrity
    • A. 

      True

    • B. 

      False

  • 15. 
    Syntax for Referential integrity?
    • A. 

      Foreign key(field_name)references table_name(field_name)

    • B. 

      Foreign key(field_name)references(field_name) on delete cascade

    • C. 

      Foreign key(field_name)references table_name(field_name) on delete cascade

    • D. 

      Foreign key(field_name)references table_name(field_name) ondelete cascade

  • 16. 
    An automatic COMMIT occurs when:
    • A. 

      DDL statement is issued

    • B. 

      DCL statement is issued

    • C. 

      Normal exit from SQL*PLUS without issuing explicit COMMIT or ROLLBACK

    • D. 

      None of the above

  • 17. 
    Zero is equivalent to null?
    • A. 

      True

    • B. 

      False

  • 18. 
    When two users access the same table's specific row simultaneously , it is possible to update the data before one commits
    • A. 

      True

    • B. 

      False

  • 19. 
    Which statement cannot be rolled back and committed automatically
    • A. 

      DDL

    • B. 

      DML

    • C. 

      TCL

    • D. 

      NONE OF THE ABOVE

  • 20. 
    Which are the types of locks?
    • A. 

      Automatic

    • B. 

      Manual

    • C. 

      Automatic and manual

    • D. 

      None of the above