Part 10
The value a field will assume unless the user enters an explicit value for an instance of that field is called a(n): A) default value. B) null value. C) range control. D) gurand.
A) default value
An advantage of partitioning is: A) efficiency. B) remote optimization. C) extra space and update time. D) both A and B.
A) efficiency.
In most cases, the goal of ________ dominates the design process. A) efficient data processing B) security C) quick pointer updates D) shorter design times
A) efficient data processing
The smallest unit of application data recognized by system software is a: A) field. B) row. C) data type. D) column.
A) field.
Database access frequencies are estimated from: A) transaction volumes. B) user logins. C) security violations. D) none of the above.
A) transaction volumes.
Horizontal partitioning makes sense: A) when different categories of a table's rows are processed separately. B) when less security is needed. C) when partitions must be organized the same. D) when all of the above are true.
A) when different categories of a table's rows are processed separately.
All of the following are common denormalization opportunities EXCEPT: A) two entities with a one-to-one relationship. B) a one-to-many relationship. C) a many-to-many relationship with nonkey attributes. D) reference data.
B) a one-to-many relationship.
All of the following are valid datatypes in Oracle 11g EXCEPT: A) varchar2. B) boolean. C) blob. D) number.
B) boolean.
A detailed coding scheme recognized by system software for representing organizational data is called a(n): A) DBMS code. B) data type. C) SQL. D) DB layout.
B) data type.
Designing physical files requires ________ of where and when data are used in various ways. A) maps B) descriptions C) keys D) hints
B) descriptions
Distributing the rows of data into separate files is called: A) normalization. B) horizontal partitioning. C) vertical partitioning. D) file allocation.
B) horizontal partitioning.
A key decision in the physical design process is: A) knowing the user base. B) selecting structures. C) deciding on the monitor. D) all of the above.
B) selecting structures.
In which data model would a code table appear? A) Conceptual B) Logical C) Physical D) Data layout
C) Physical
Sensitivity testing involves: A) checking to see if your teeth hurt when you brush. B) seeing how accurate data are. C) checking to see if missing data will greatly impact results. D) none of the above.
C) checking to see if missing data will greatly impact results.
The storage format for each attribute from the logical data model is chosen to maximize ________ and minimize storage space. A) query design B) programmer productivity C) data integrity D) data integration
C) data integrity
An integrity control supported by a DBMS is: A) substitute estimates. B) security. C) range control. D) GUI guards.
C) range control.
Which of the following is an objective of selecting a data type? A) Represent a small number of possible values B) Maximize storage space C) Limit security D) Improve data integrity
D) Improve data integrity
A method for handling missing data is to: A) substitute and estimate for the missing data. B) track missing data with special reports. C) perform sensitivity testing. D) all of the above.
D) all of the above.
A requirement to begin designing physical files and databases is: A) normalized relations. B) definitions of each attribute. C) technology descriptions. D) all of the above.
D) all of the above.
All of the following are objectives when selecting a data type EXCEPT: A) represent all possible values. B) improve data integrity. C) support all data manipulations. D) use a lot of storage space.
D) use a lot of storage space.
A default value is the value that a field will always assume, regardless of what the user enters for an instance of that field.
False
Adding notations to the EER diagram regarding data volumes and usage is of no value to the physical design process.
False
Denormalization is the process of transforming relations with variable-length fields into those with fixed-length fields.
False
Horizontal partitioning is very different from creating a supertype/subtype relationship.
False
Horizontal partitioning refers to the process of combining several smaller relations into a larger table.
False
One method to handle missing values is to substitute an exact value.
False
SOX stands for the Sorbet-Oxford Act.
False
The logical database design always forms the best foundation for grouping attributes in the physical design.
False
The smallest unit of named application data is a record.
False
A range control limits the set of permissible values that a field may assume.
True
Denormalization almost always leads to more storage space for raw data.
True
Efficient database structures will be beneficial only if queries and the underlying database management system are tuned to properly use the structures.
True
Keeping the zip code with the city and state in a table is a typical form of denormalization.
True
One decision in the physical design process is selecting structures.
True
One objective of selecting a data type is to minimize storage space.
True
Requirements for response time, data security, backup and recovery are all requirements for physical design.
True
Sensitivity testing involves ignoring missing data unless knowing a value might significantly change results.
True