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This set of DataBase Management System (DBMS) Multiple Choice Questions & Answers (MCQs) focuses on Database Management System Set 56

Q1 | A table that contains one or more repeating groups is in which normal form?
  • 1NF
  • 2NF
  • 3NF
  • Unnormalized Form
Q2 | A relation is said to be in 3 NF if(i) it is in 2 NF (ii) non-key attributes are independent of one another (iii) key attribute is not dependent on part of a composite key (iv) has no multi-valued dependency
  • i and iii
  • i and iv
  • i and ii
  • ii and iv
Q3 | Given the following relation it is not 3 NF because Student (roll no, name, course no, course max. marks, year of study, address)
  • it is not in 2 NF
  • it does not have composite key
  • non-key attributes course no and course max. marks are functionally dependent
  • it has more than 3 non-key attributes
Q4 | Given the following relation Student (roll no, name, course no, course max. marks, year of study, address)The corresponding 3 NF relations are
  • student (roll no, name, year of study, address) course (course no, course max. marks)
  • student ( roll no, name, year of study, address) student (roll no, course no) course (course no, course max. marks)
  • student (roll no , name, address) year (roll no, year of study) course (course no, course max. marks)
  • student (roll no, name, address) course (course no, course max. marks, year of study)
Q5 | BoyeCodd Normal Form (BCNF) is needed when
  • two non-key attributes are dependent
  • there is more then one possible composite key
  • there are two or more possible composite overlapping keys and one attributeof a composite key is dependent on an attribute of another composite key
  • there are two possible keys and they are dependent on one another
Q6 | A relation is said to be in BCNF when
  • it has overlapping composite keys
  • it has no composite keys
  • it has no multivalued dependencies
  • it has no overlapping composite keys which have related attributes
Q7 | A 3 NF relation is converted to BCNF by
  • removing composite keys
  • removing multivalued dependencies
  • dependent attributes of overlapping composite keys are put in a separateRelation
  • dependent non-key attributes are put in a separate table
Q8 | BCNF is needed because
  • otherwise tuples may be duplicated
  • when a data is deleted tuples may be lost
  • updating is otherwise difficult
  • when there is dependent attributes in two possible composite keys one of the attributes is unnecessarily duplicated in the tuples
Q9 | Given the relation Supplier(s_id, p_order, s_name, qty) Given that there is a unique s_name for each s_id and that s_id, p_order is a composite key, find the correct statement among the following: i. this relation is a BCNF ii. this is 3 NF relation iii. this is a 2 NF relation iv. this is a 1 NF relation
  • i and ii
  • ii and iii
  • i and iv
  • i and iii
Q10 | A relation project guidance Project Guidance(professor, project, student no. st-name, dept) A professor can give many projects to many students A project will have many students A project may be guided by many professors The 4 NF relation corresponding to this are
  • Prof_Project (professor, st_name, dept) Proj_stud (project, student no.)
  • Prof_stud (professor, student no) Proj_stud (project, student no)
  • Student (student no, st_name, dept) Student (student no, st_name, dept)
  • Professor(professor, project) Professor( professor, project, dept) Student (student no, st_name, dept)
Q11 | A 3 NF relation is split into 4 NF
  • by removing overlapping composite keys
  • by splitting into relations which do not have more than one independent multi valued dependency
  • removing multivalued dependency
  • by putting dependent non-key attribute in a separate table
Q12 | Using the SQL GROUP BY phrase with a SELECT statement can help detect which ofthe following problems?
  • The multivalue, multicolumn problem
  • The inconsistent values problem
  • The missing values problem
  • The general-purpose remarks column problem
Q13 | What SQL command will allow you to change the table STUDENT to add the constraint named GradeCheck that states that the values of the Grade column must be greater than 0?
  • ALTER TABLE STUDENT ALTER CONSTRAINT GradeCheck (Grade > 0);
  • ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck (Grade > 0);
  • ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck CHECK (Grade > 0);
  • None of the above is correct.
Q14 | The NOT EXISTS keyword will be true if:
  • any row in the subquery meets the condition.
  • all rows in the subquery fail the condition.
  • both of these two conditions are met.
  • neither of these two conditions is met.
Q15 | Changing cardinalities in a database is:
  • a common database design task.
  • a rare database design task, but does occur.
  • a database design task that never occurs.
  • is impossible to do, so a new database must be constructed and the data moved into it.
Q16 | Which one of the following sorts rows in SQL?
  • SORT BY
  • ALIGN BY
  • ORDER BY
  • GROUP BY
Q17 | The SQL keyword(s) ________ is used with wildcards.
  • LIKE only
  • IN only
  • NOT IN only
  • IN and NOT IN
Q18 | If a relationship has a cascade updates constraint, then if ________ in the parent table is changed, then the same change will automatically be made to any corresponding foreign key value.
  • the primary key
  • any alternate key
  • a surrogate key
  • a foreign key
Q19 | For every relationship, how many possible types of actions are there when enforcingminimum cardinalities?
  • Two
  • Three
  • Four
  • Six
Q20 | In creating a procedure, you may get a message if you have compile errors. Which of the following is true?
  • The line numbers reported match the line numbers you see in your text editor.
  • SQL*Plus will automatically show the errors to you.
  • To see the errors, enter SHOW ERRORS in SQL*Plus.
  • If there are no syntax errors, you will receive the message "NO ERRORS.
Q21 | Which of the following is not true about indexes?
  • Indexes are created to enforce uniqueness on columns.
  • Indexes are created to enable fast retrieval by column values.
  • Columns that are frequently used with equal conditions in WHERE clauses are good candidates for indexes.
  • Indexes are created with the ALTER TABLE command.
Q22 | In ……….. normal forms, any multivalued attributes have been removed.
  • First
  • Second
  • Third
  • Fourth
Q23 | A (n) …………….. is an attribute in a relation that serves as a primary key of another relation in the same.
  • Composite key
  • Foreign key
  • Identifier key
  • Primary key
Q24 | In the process of decomposition is called as
  • Normalization
  • Generalization
  • Aggregation
  • Specalization
Q25 | A relation Schema R is in ……….. if it is in 3NF and satisfies an additional constant thatfor every FD X->A. X must be a candidate key.
  • 1 NF
  • 2 NF
  • 3 NF
  • BCNF