Modern Database Management - Self Check 05
Adding notations to the EER diagram regarding data volumes and usage is of no value to the physical design process
F
Along with table scans, other elements of a query can be processed in parallel
F
An extent is a named portion of secondary memory allocated for the purpose of storing physical records
F
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
A file organization is a named portion of primary memory
False
A join index is a combination of two or more indexes
False
A key is a data structure used to determine the location of rows in a file that satisfy some condition
False
________ partitioning is a method in which each partition is defined by a range of values for one or more columns of a normalized table
Range
________ is often used to decide whether or not missing data can be ignored
Sensitivity testing
A tablespace is a named set of disk storage elements in which physical files for the database tables may be stored
T
Clustering allows for adjacent secondary memory locations to contain rows from several tables
T
Denormalization almost always leads to more storage space for raw data
T
A hashing algorithm is a routine that converts a primary key value into a relative record number
True
A pointer is a field of data that can be used to locate a related field or record of data.
True
A range control limits the set of permissible values that a field may assume
True
A(n) ________ is defined by the tables and column of columns by which the tables are joined
cluster
________ can be built into the physical structure of fields for many database management systems
data integrity controls
A ________ is a detailed coding scheme recognized by system software, such as a DBMS, for representing organizational data
data type
Denormalization is the process of transforming relations with variable-length fields into those with fixed-length fields
f
Free range partitioning is a type of horizontal partitioning in which each partition is defined by a range of values for one or more columns in the normalized table
f
Horizontal partitioning is very different from creating a supertype/subtype relationship
f
Horizontal partitioning refers to the process of combining several smaller relations into a larger table
f
Indexes are most useful on small, clustered files
f
One method to handle missing values is to substitute an exact value
f
Parallel query processing speed is not significantly different from running queries in a non-parallel mode
f
Reduced uptime is a disadvantage of partitioning
f
The query processor always knows the best way to process a query
f
The smallest unit of named application data is a record
f
Using an index for attributes referenced in ORDER BY and GROUP BY clauses has no significant impact upon database performance.
f
Vertical partitioning means distributing the columns of a table into several separate physical records
f
A routine that converts a primary key value into a relative record number is called a(n)______
hashing algorithm
A(n) ________ overrides whatever query plan Oracle would naturally create for a query based upon the query optimizer.
hint
Distributing the rows of data into separate files is called ________
horizontal partitioning
________ distributes the columns of a table into several separate physical records
horizontal partitioning
A table or other data structure used to determine the location of rows in a file that satisfy some condition is called a(n)______
index
An index on columns from two or more tables that come from the same domain of values is called a(n) ________ index
join
Because data table row locations are dictated by the hashing algorithm, only one ________ can be used for hashing-based retrieval
key
A strategy for breaking apart queries and running each part on separate processors is called
parallel query processing
A ________ limits the set of permissible values a field must assume
range control
A ________ key is one field or a combination of fields for which more than one record may have the same combination of values
secondary
Fast data retrieval is one factor to consider when choosing a file organization for a particular database file.
t
Hash partitioning spreads data evenly across partitions independent of any partition key value
t
In a sequential file, the records are stored in sequence according to primary key
t
Indexes are most useful for columns that frequently appear in WHERE clauses of SQL commands, either to qualify the rows to select or for linking
t
One decision in the physical design process is selecting structures
t
One objective of selecting a data type is to minimize storage space
t
Security is one advantage of partitioning
t
A ________ is a named set of disk storage elements in which physical files for database tables may be stored
tablespace
Denormalization is the process of transforming normalized relations into ________ physical record specifications
unnormalized
Indexes are most useful for columns that frequently appear in ________ clauses of SQL statements
where