| Q 1: | The following query written in relational algebra will find:
|
| (1) | All branches in Ga |
| (2) | All customers in any branch other than goa |
| (3) | All customers who have an account at all branches in Goa |
| (4) | All customers who do not have an account in any branch in Goa |
| Correct Answer: All customers who do not have an account in any branch in Goa | |
| Q 2: | The transaction T2 could read a database object A that has been modified by another transaction T1 which has not yet committed, such concept is called as |
| (1) | Dirty read |
| (2) | dirty write |
| (3) | lazy read |
| (4) | lazy write |
| Correct Answer: Dirty read | |
| Q 3: | Which one of the following is a correct notation in ER diagrams? |
| (1) | Entites are oval |
| (2) | Relationships are rectangles |
| (3) | Attributes are diamonds |
| (4) | Weak entities are double rectangles |
| Correct Answer: Weak entities are double rectangles | |
| Q 4: | Consider the following relation that stores information about offices, telephones and occupants of offices, Office (OfficeNum, Telephone Num, Occupant) Each office has a unique office number. There is only one telephone in each office and the telephone number is unique. Each office is occupied by only one person although a person may have more than one office. Occupant is a unique identification for persons occupying rooms. Which one of the following is correct? |
| (1) | OfficeNum and TelephoneNum are both candidate keys. |
| (2) | OfficeNum, TelephoneNum and (OfficeNum, TelephoneNum) are all candidate keys. |
| (3) | (OfficeNum, Occupant) and (TelephoneNum, Occupant) are the candidate keys. |
| (4) | OfficeNum must be the primary key. |
| Correct Answer: OfficeNum and TelephoneNum are both candidate keys. | |
| Q 5: | Which of the following is correct? |
| (1) | A Cartesian product of two relations is the same as their union. |
| (2) | A join of two relations is a selection on their Cartesian product. |
| (3) | A join is always an equi join or a natural join |
| (4) | The degree of the equi join of two relation is the same as the degree of the natural join of the same relations. |
| Correct Answer: A join of two relations is a selection on their Cartesian product. | |
| Q 6: | Which of the following is not true about OLAP? |
| (1) | OLAP can deal with transactional data. |
| (2) | In OLAP storage size can vary from 100 GB upto 1 TB |
| (3) | OLAP can access Millions of records. |
| (4) | Dimensional view of data is flat relational view in OLAP. |
| Correct Answer: Dimensional view of data is flat relational view in OLAP. | |
| Q 7: | Consider the following set of functional dependencies: A→B A C CD → E B-D E-A Which of the following functional dependencies is NOT implied by the above set? |
| (1) | CD → AC |
| (2) | BC→ CD |
| (3) | BD → CD |
| (4) | AC → BC |
| Correct Answer: BD → CD | |
| Q 8: | The employee's salary should not be more than Rs. 6000. This is |
| (1) | Integrity constraint |
| (2) | Referential constraint |
| (3) | Over-defined constraint |
| (4) | Feasible constraint |
| Correct Answer: Integrity constraint | |
| Q 9: | If adjacency relation of vertices in a graph is represented in a table Adj(x,y), then which of the following Queries cannot be expressed by a relational algebra expression of constant length ? |
| (1) | List all vertices adjacent to given vertex |
| (2) | List all vertices which have self-loops |
| (3) | List all vertices which belong to cycle of less than three vertices |
| (4) | List all vertices reachable from a given vertex |
| Correct Answer: List all vertices reachable from a given vertex | |
| Q 10: | Which of the following is true of the data manipulation language (DML)? |
| (1) | It refers to data using physical addresses |
| (2) | It cannot interface with high-level progamming language |
| (3) | It is used to define the physical characteristics of each record |
| (4) | None of these |
| Correct Answer: None of these | |
