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UNIT I Previous Questions

  1. Explain the role of database administrator.

  2. Explain with a suitable example, converting an E-R diagram into a table.

  3. Mention and explain primitive operations in reltional algebra.

  4. What are keys? Mention and explain various keys used.

  5. What are integrity constraints?Explain.

  6. Compare and contrast file systems versus DBMS. Explain difference between logical and physical data independence.

  7. Consider the following schema: suppliers( sid: integer, sname:string, address:string) ; Parts(pid:integer, pnme:string, color:string) ; Catalog(sid:integer, pid:integer, cost:real). write queries in relational algebra and TRC:

    1. Find names of suppliers who supply some red part.

    2. Find sids of suppliers who supply every part.

    3. Finf pids of parts that are supplied by at least two different suppliers.

    4. Find the pids of the most expensive parts supplied by suppliers named Tata

  8. What are the salient features of SQL?

  9. Consider the Sailors, Boats and Reserves schema in the text book and write the following queries in SQL;

    1. Find the names of sailors who have reserved boat no: 103

    2. Find the color of boats reserved by Sudhakar.

    3. Find the names of sailors who have reserved both a red and a green boat.

    4. Find the sailors whose rating is better than some sailor called Sudhakar.

  10. Distinguish between DDL and DML

  11. Explain about Generalisation and Aggregation

  12. Compare SQL and QBE.

  13. Explain about Domain Calculus expression.

  14. Write short notes on a)Entities and attributes b)Strong and Weak Entities c)Cross products and Joins.

  15. Explain different levels of abstraction in a DBMS.. What is data independence? Explain different types of Data Independence.

  16. Explain TRC and DRC with examples. List two reasons why null values are introduced into databases. Explain nested subqueries in SQL.

  17. Differentiate between binary and ternary relationships.

  18. Let R=(A,B,C) and let r1 and r2 be relations on schema R. Give an expression in SQL that is equivalent to each of the following queries:

    1. r1 U r2  2. r1 - r2 3. Pi(AB) (r1)  Join Pi(BC) (r2)

  19. Construct an ER digrm for a cr insurance company that has a set of customers, each of whom owns one or more cars. Each car has associated with it zero to any number of recorded accidents.

  20. Describe the extended ER features.

  21. Draw the ER diagram for the banking Enterprise and explain.

  22. Describe fundamental operations of relational algebra with examples. Discuss natural join with an example.

  23. Explain various built in functions of SQL.