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Database Management System : PYQ (in Hindi)
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In this lesson , I have discussed DSSSB Computer Teacher - Subject - wise Previous Year Questions With Detailed Analysis.

Sweta Kumari
YouTuber (channel : GATE NoteBook) | Verified Educator | 2+ year Online Teaching Experience

Unacademy user
Very detailed explanation how to prepare geography. Can you make such detailed course for other subjects for CSE? This course is immensely beneficial for a new starter.
Thank you so much madam
Sweta Kumari
a year ago
Your Welcome Harshita :)
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  2. ABOUT ME Sweta Kumari Done B.TECH (CSE) From GGSIPUI Software Engineer | Online Educator at Unacademy for Empowering Technical Programming in Students Sweta Kumari Unscademy Top Educator 2017 Sweta Kumari top educator Learning is Earning - The more you learn, The more you Earn. 2017 FOLLOW M FOLLhtips:/



  5. 1. Which of the following is TRUE? a) Every relation in 2NF is also in BCNF b) A relation R is in 3NF if every non-prime attribute of R is fully functionally dependent on every key of R c) Every relation in BCNF is also in 3NF d) No relation can be in both BCNF and 3NF 7

  6. 1NF (First Normal Form) 2NF (Second Normal Form) Rules Each table cell should contain a single value. Each record needs to be unique. Rules Rule 1- Be in 1NF Rule 2- Single Column Primary Key 7

  7. 3NF (Third Normal Form) Rules Rule 1- Be in 2NF Rule 2- Has no transitive functional dependencies Boyce-Codd Normal Form (BCNF) Even when a database is in 3rd Normal Form, still there would be anomalies resulted if it has more than one Candidate Key. Sometimes is BCNF is also referred as 3.5 Normal Form.

  8. 2. Which one of the following statements about normal forms is FALSE? a) BCNF is stricter than 3NF b) Lossless, dependency-preserving decomposition into 3NF is always possible c) Lossless, dependency-preserving decomposition into BCNF is always possible d) Any relation with two attributes is in BCNF 7

  9. . If a relation is in 3NF, which of the above points is guaranteed>both are neccessary .If a relation is in BCNF , which of the above points is guaranteedlossless join is guaranteed but dependency preserving may or may not be guaranteed 7

  10. 3. Which normal form is considered adequate for normal relational database design? a) 2NF b) 5NF c) 4NF d) 3NF 7

  11. operator is used to compare a value to a list of literals 4 values that have been specified a) LIKE b) COMPARE c) BETWEEN d) IN 7

  12. 6. The clause ALTER TABLE in SQL can be used to a) add an attribute b) delete an attribute c) alter the default value of an attribute d) All of the above 7

  13. 7. In SQL testing whether a sub query is empty is done using a) DISTINCT b) UNIQUE c) NULL d) EXISTS 7

  14. The SQL EXISTS Operator . The EXISTS operator is used to test for the . The SELECT DISTINCT statement is used to return only distinct (different) existence of any record in a subquery. values. SELECT DISTINCT Syntax SELECT DISTINCT column1, column2,EXISTS Syntax FROM table_name; . The EXISTS operator returns true if the subquery returns one or more records. . SELECT column_name(s) FROM table_name WHERE EXISTS A field with a NULL value is a field with (SELECT column_name FROM table_name no value. WHERE condition); The UNIQUE constraint ensures that all values in a column are different.

  15. 8. Which of the following statement on the view concept in SQL is invalid a) All views are not updatable. b) The views may be referenced in an SQL statement whenever tables are referenced. c) The views are instantiated at the time they are referenced and not when they are defined. d) The definition of View should not have a Group By clause in it. 7

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