database management ch 2 quiz

which of the following is the term for a prinary key of one relation placed into a second relation to establish a relationship

• a candidate key

• field key

• relocated key

• foreign key

The actual implementation of relational databases were delayed for many years after the theory was developed. What caused this delay?

• Computer scientist couldn't correctly program the software

• The cost of computers were too high for companies to afford both the computer and a relational database

• There was no demand for relational database syste

• Computers of the time did not have the processing power to make relational database software systems pratical.

Which of the following is used to rleat one table to another

• composite key

• relational key

• primary key

• foreign key

Which of the following is true about a relation?

• The columns and rows can be in any order

• The rows must be in order by the primary key values

• The columns must be in alphabetical order

• The columns must be in alphabetical order and the rows must be in order by the primary key

Which of the following is Not an attribute?

• Height

• Person

• Weight

• Eye color

Which of the following is true regarding null values

• A null value is always means no value for field is appropriate.

• A null value always means the value is unknown to be blank

• A null value is always unclear .You can't be sure what IT MEANS

• a NULL ALUE ALWAYS MEANS THE VALUE IS UNKNOW.

Two attributes (columns) that have the same range of values representing the same thing demonstrate which of the following properties

• the same surrogate values

• the same domain of values

• the same values of identity

• the same determinate values

which of the following is an entity?

• the size

• car

• horsepower

• color

• column1

• column2

• column3

• column4

All the following are true with respect to surrogate keys EXCEPT one. Which of the following is NOT true of surrogate keys? In other words, which statement below is false?

• surrogate key are meaningful to the users

• surrogate keys are usually numeric.

• surrogate keys are usually generated by the DBMS.

• surrogate keys are unique