Modern Database Management - Self Check 05

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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


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