1. The conceptual model is the basis for the description of the main data objects, avoiding details.
1. ____________ is a technique that might be employed to improve query performance.
a. Performance tuning
d. All of the above
1. When a table"s attributes depend on the 'key, the whole key, and nothing but the key,' the table exhibits ___________.
a. partial dependency
c. full-functional dependency
1. If you need to determine the value of inventory held on hand, and you want to display the results in a column labeled TotValue, which of the following would you use?
a. SELECT P_DESCRIPT, P_ONHAND, P_PRICE, (P_ONHAND + P_PRICE) COLUMN AS TOTVALUE FROM PRODUCT;
b. SELECT P_DESCRIPT, P_ONHAND, P_PRICE, (P_ONHAND - P_PRICE) AS TOTVALUE FROM PRODUCT;
c. SELECT P_DESCRIPT, P_ONHAND, P_PRICE, (P_ONHAND * P_PRICE) AS TOTVALUE FROM PRODUCT;
d. SELECT P_DESCRIPT, P_ONHAND, P_PRICE, (P_ONHAND / P_PRICE) HEADING AS TOTVALUE FROM PRODUCT;
1. All attributes for a specific entity can be grouped together as a(n)
6) The hierarchical database model depicts a set of _______________relationships.
1. A database model is a collection of logical constructs used to represent the data structure and relationship. Database models are
a. implementation and relationship.
b. conceptual and Implementation.
c. conceptual and Relationship.
1. Denormalization produces a lower normal form and is often recommended for small databases with few users.
1. Which of the following situation demonstrates data redundancy?
a. A customer"s address is stored in the Customer File and a sales agent"s address is stored in the Sales Agent File
b. A customer"s address is stored in the Customer File and the Invoice File.
c. A customer"s address is stored in the Customer File.
d. All of the above
1. Which of the following is NOT true regarding aggregate functions?
a. All aggregate functions may be used on numeric data.
b. The Count(column) function will count all non-null values in the specified column.
c. All aggregate functions may be used on character data.
d. The Count(*) function will count all rows whether null values exist or not.
1. Because a partial dependency can exist only if a table"s primary key is composed of several attributes, a table whose primary key consists of only a single attribute must automatically be in 2NF if it is in 1NF.
1. Data fragmentation is a situation where a database is divided into subsets of data and stored at multiple locations.
1. MPSD is a distributed database environment with ___________ processing and a __________ database.
a. centralized, distributed
b. centralized, centralized
c. distributed, centralized
d. distributed, distributed
1. A lock that defines how transactions acquire and relinquish locks is known as a(n)
a. shared lock.
c. exclusive lock.
d. binary lock.
e. two-phase lock.
1. Every transaction must start with the database in a consistent state and must return the database to a consistent state after it has completed.
1. All transactions properties must display
a. atomicity, durability, serializability, and isolation.
b. durability and isolation.
c. atomicity, serializability, and durability.
d. serializability, durability, and isolation.
1. The DDBMS transparency features are:
a. distribution and Transaction transparencies
b. failure and Performance transparencies
c. heterogeneity transparencies
d. b only
e. all of the above
1. Normalization reduces data redundancy in the database.
1. A lock that specifically reserves access for the transaction that locked the object is known as a(n)
a. binary lock.
b. two-phase lock.
d. shared lock.
e. exclusive lock.
1. Because RDBMS hides the system"s complexity from the user/designer,
a. data management is very difficult.
b. data management is easier.
c. it does not exhibit structural independence.
d. it does not exhibit data independence.
1. The 'vertical' subset of data is the result of adding a WHERE clause to a SELECT statement.
1. A table that is in 2NF and contains no transitive dependencies is said to be in
1. In database design, a 1:1 relationship is uncommon and often indicates a design flaw.
1. A data warehouse stores historical data.
1. Which of the following can be used to retrieve a 'horizontal' subset of data?
a. Selecting all attributes
b. Selecting specific attributes
c. GROUP BY clause
d. WHERE clause
1. A superkey is any key that uniquely identifies each
a. entity in a table.
b. object in a table.
d. structure in a table.
Answer: True d a c c a b True b a... View the full answer