Database Management Systems Set 35

Database Management Systems

Questions   341 to 350




341.
A foreign key must
(a)    Be numeric
(b)    Be unique
(c)     Be defined in all tables within the database
(d)    Match the field value of a primary key in a related table
(e)     Contain only one attribute.
342.
Within a table, the primary key must be unique so that it will identify each row. Which of the following constraints exhibits the above criterion?
(a) Referential integrity                                       (b) Entity integrity
(c) Enforced integrity                                           (d) Domain integrity
(e) Check integrity.
343.
You want the contents of the PRODUCT table listed by P_Price in ascending order listing P_CODE, P_DESCRIPT, P_INDATE, and P_PRICE and with P_INDATE < ‘8-oct-05’.
The command will be
(a)    Select p_code, p_descript, p_indate, p_price from product where P_INDATE < ‘8-oct-05’ sequence by p_price;
(b)    Select p_code, p_descript, p_indate, p_price from product where P_INDATE < ‘8-oct-05’ list by p_price;
(c)     Select p_code, p_descript, p_indate, p_price from product order by p_price asc where P_INDATE < ‘8-oct-05’;
(d)    Select p_code, p_descript, p_indate, p_price from product where P_INDATE < ‘8-oct-05’ ascending by p_price;
(e)     Select p_code, p_descript, p_indate, p_price from product where P_INDATE < ‘8-oct-05’order by p_price asc.
344.

In the above the relation A,B,C,D are the attributes and (A,B) are the key attributes. The arrows represent the functional dependencies. Which of the following statements is true based upon the above diagram?
(a) The above relation has partial dependency (b) The above relation is not in 1NF
(c) The above relation is not in 2NF                 (d) The above relation is in BCNF
(e) The above relation is in 3NF, but not in BCNF.
345.
Which of the following structures eliminates the redundant storage of search key values in B+ trees?
(a) B-Trees                                                             (b) Indexed sequential file (c) AVL trees
(d) Hash structure                                                (e) Graph structure.
346.
Which of the following is referred to as a sequential storage device?
(a) Tape storage                                                   (b) Flash memory
(c) Optical storage                                                (d) Cache                       (e) Main memory.
347.
Which of the following statements is false with respect to the storage of the database?
(a)    A database is mapped into a number of different files, which are maintained by the underlying operating system
(b)    Each file is partitioned into fixed-length storage units called blocks
(c)     A major goal of database system is to maximize the number of block transfers between disk and memory
(d)    Both (a) and (b) false
(e)     Both (b) and (c) false.
348.
In order to maintain transactional integrity and database consistency, what technology does a DBMS deploy?
(a) Triggers                    (b) Pointers                    (c) Locks                        (d) Cursors (e) Deadlocks.
349.
A lock that allows concurrent transactions to access different rows of the same table is known as a
(a) Database-level lock                                       (b) Table-level lock
(c) Page-level lock                                                (d) Row-level lock
(e) Field-level lock.
350.
Which of the following is/are reason(s) for the existence of variable length records in database systems?
(a)    Storage of multiple record types in a file
(b)    Record types that allow variable lengths for one or more fields
(c)     Record types that allow repeating fields
(d)    All of the above
(e)     None of the above.

Answers


341.
Answer :   (d)
Reason :   (d) is the correct option.
342.
Answer :   (b)
Reason :   When there is a primary key table is said to exhibit entity integrity.
343.
Answer :   (e)
Reason :   (e) is the correct syntax for the query.
344.
Answer :   (e)
Reason :   A relation is said to be in BCNF if all the FDs are either trivial or the determinant is a candidate key. In C→ B, C is not a candidate key. So the relation is not in BCNF. Since no transitive dependencies are not there and it is in the 2NF the relation is in 3NF.
345.
Answer :   (a)
Reason :   The redundant storage of search key values in B+ trees is eliminated in B Trees.
346.
Answer :   (a)
Reason :   Tapes are sequential storage devices.
347.
Answer :   (c)
Reason :   Only c option is false because major goal of database system is to minimize the number of block transfers between disk and memory.
348.
Answer :   (c)
Reason :   Locks are used to maintain database consistency.
349.
Answer :   (d)
Reason :  
350.
Answer :   (d)
Reason :   Variable length records arise out of all the given reasons.
<< Prev  1...  2...  3...  4...  5...  6...  7...  8...  9...  10...  11...  12...  13...  14...  15...  16...  17...  18...  19...  20...  21...  22...  23...  24...  25...  26...  27...  28...  29...  30...  31...  32...  33...  34...  35...  36...  Next >>


3 comments :

  1. I'm so glad to have found something informative in your site. Thanks for sharing.

    jandi

    www.triciajoy.com

    ReplyDelete
  2. Thanks to the writer of this article. I appreciate your effort in making this informational blogs. I know it's not easy to do this but you have done a really great job. Congrats. I'm pretty sure your readers enjoying it a lots.


    Rica
    www.imarksweb.org

    ReplyDelete
  3. Did you know that you can make money by locking premium pages of your blog / website?
    Simply join AdWorkMedia and run their Content Locking tool.

    ReplyDelete