Deck 14: Database Design

Question 1

A file is a collection of similar records.

Answer 1

True

Question 2

A database is a collection of interrelated files.

Answer 2

True

Question 3

An historical advantage of using conventional files has been processing speed. They can be optimized for the access of the application.

Answer 3

True

Question 4

Duplication of data items in multiple files is normally cited as the principal disadvantage of file-based systems.

Question 5

A database is not necessarily dependent on the applications that use it.

Question 6

Given the large capacity disks that are now available, database administrators no longer have to be concerned about estimating how much disk capacity is required for a new database.

Question 7

It is important for the database administrator to estimate how much disk capacity is required for a new database to ensure that sufficient disk space is available.

Question 8

Conventional files are relatively difficult to design and implement because they are normally designed for use with multiple applications or information systems.

Question 9

Files tend to be built around single applications without regard to other, future applications.

Question 10

A significant disadvantage of conventional files is their inflexibility and non-scalability.

Question 11

A significant advantage of conventional files is their flexibility and scalability.

Question 12

As legacy file-based systems and applications become candidates for reengineering, the trend is overwhelmingly in favor of replacing file-based systems and applications with database systems and applications.

Question 13

As enterprise systems and applications are re-engineered, the trend is overwhelmingly in favor of replacing database systems and applications with legacy file-based systems and applications.

Question 14

The principal advantage of database systems is the ability to share the same data across multiple applications and systems.

Question 15

A principal advantage of the database approach is that you can build a single super-database that contains all data items of interest to an organization.

Question 16

Most organizations build several databases, each one sharing data with several information systems. Thus, there will be some redundancy between databases.

Question 17

Most organizations build several databases leading to significant and uncontrolled redundancy between databases.

Question 18

Database technology offers the advantage of storing data in flexible formats.

Question 19

A disadvantage of database technology is the lack of flexibility in data storage formats.

Question 20

Data independence refers to the fact that databases are defined separately from the information systems and application programs that will use them.

Question 21

Database technology provides superior scalability, meaning that the database and the systems that use it can be grown or expanded to meet the changing needs of an organization.

Question 22

Database technology provides better technology for client/server and network computing architectures.

Question 23

You see a return to conventional file-based architectures today because they are better technology for client/server and network computing architectures.

Question 24

File technology is more complex than database technology.

Question 25

While a database management system (DBMS) is somewhat slower than file technology, these performance limitations are rapidly disappearing.

Question 26

The cost of developing databases is higher than the cost of developing files.

Question 27

A field is the physical implementation of a data attribute. Fields are the smallest unit of meaningful data to be stored in a file or database.

Question 28

A file is the physical implementation of a data attribute. Files are the smallest unit of meaningful data to be stored.

Question 29

A primary key is a field whose values identify one and only one record in a file.

Question 30

A foreign key is a field whose values identify one and only one record in the same file.

Question 31

A secondary key is an alternate identifier for a database. Its value may identify either a single record or a subset of all records.

Question 32

A primary key might be created by combining two or more fields. In this situation, it is called a concatenated key.

Question 33

An index is frequently created for keys.

Question 34

Foreign keys are pointers to the records of a different file in a database.

Question 35

A descriptive field is any other non-key field that stores business data.

Question 36

A record is a collection of fields arranged in a predefined format.

Question 37

A field is a collection of records arranged in a predefined format.

Question 38

A blocking factor allows different records in the same file to have different lengths.

Question 39

Most database technologies impose a fixed-length record structure, meaning that each record instance has the same fields, same number of fields and same logical size.

Question 40

Some database systems can compress unused fields and values to conserve disk storage space.

Question 41

Variable-length record structures allow different records in the same file to have different lengths.

Question 42

When a computer program "reads" a record from a database, it actually retrieves a group or block (or page.) of records at a time. This approach minimizes the number of actual disk accesses.

Question 43

A variable-length record structure means that each record instance has the same fields, same number of fields and the same logical size.

Question 44

A fixed-length record structure means that each record instance can have different fields, a different number of fields, as long as the length (size) of the record is always fixed at the same size.

Question 45

A blocking factor is the number of physical records included in a single read or write operation.

Question 46

The set of all occurrences of a given record structure in a database system is frequently called a table.

Question 47

Master files or tables contain records that are relatively permanent. Thus, once a record has been added to a master file, it remains in the system indefinitely. The values of fields for the record will change over its lifetime, but the individual records are retained indefinitely.

Question 48

Transaction files or tables contain records that describe business events. The data describing these events normally has a limited useful lifetime.

Question 49

Document files and tables contain stored copies of historical data for easy retrieval and review without the overhead of regenerating the document.

Question 50

Archival files and tables contain master and transaction file records that have been moved from on-line storage to off-line storage.

Question 51

Table look-up files contain relatively static data that can be shared by applications to maintain consistency and improve performance.

Question 52

Audit files are special records of updates to other files, especially master and transaction files. They are used in conjunction with archival files to recover "lost" data. Audit trails are typically built into better database technologies.

Question 53

In today's database environment, the database technology itself usually predetermines and/or limits file organization for all tables contained in the database.

Question 54

Many information systems shops hesitate to give end users access to operational databases for queries and reports.

Question 55

Data are a resource that must be controlled and managed!

Question 56

Prototyping is an alternative to doing database design.

Question 57

Once a database design and its corresponding schema have been completed, a prototype database can usually be generated very quickly.

Question 58

Most modern database management systems (DBMS) include powerful, menu-driven database generators that automatically create a DDL and generate a prototype database from that DDL.

Question 59

The advantages and disadvantages of horizontal versus vertical distribution of data are similar.

Question 60

Centralization of the database refers to the physical distribution of entire tables to multiple locations on central processing units.

Question 61

Centralization is the simplest and easiest solution to maintain.

Question 62

Centralization helps data administrators maintain an important data management rule - data should be controlled and centralized as much as possible to ensure data integrity.

Question 63

Central distribution of data refers to the physical duplication of entire tables to multiple locations.

Question 64

Operational databases are developed to support day-to-day operations and business transaction processing for major information systems.

Question 65

Few high-end, enterprise database management systems include replication technology that coordinates updates to the duplicated tables and records to maintain data integrity.

Question 66

Replication of data offers performance and accessibility advantages and reduces network traffic, but it also increases the complexity of data integrity and requires more physical storage.

Question 67

Data warehouses store data extracted from the operational databases and conventional files.

Question 68

Operational databases and conventional files store data extracted from data warehouses.

Question 69

Data mining is the term used to describe the use query tools and decision support tools that are used to generate reports and analyses off of data warehouses.

Question 70

Metadata is the data about data, such as record and field definitions, synonyms, data relationships, validation rules, help messages, etc.

Question 71

DML commands may be "called" from programming languages.

Question 72

Contemporary data architecture allows for Internet-enabled database technology.

Question 73

Examples of high-performance relational DBMSs include Oracle, IBM's DB2, and Microsoft Access.

Question 74

A data administrator is responsible for the data planning, definition, architecture, and management.

Question 75

One or more database administrators (DBAs) are responsible for the database technology, database design and construction consultation, security, backup and recovery, and performance tuning.

Question 76

Database architecture refers to the database technology including the database engine, database utilities, database CASE tools for analysis and design, and database application development tools.

Question 77

A database management system (DBMS) is specialized computer software available from computer vendors that is used to create, access, control, and manage the database.

Question 78

A data definition language (DDL) is used by the DBMS to physically establish record types, fields, and structural relationships. Additionally, the DDL defines views of the database.

Question 79

The data manipulation language (DML) is used by the DBMS to physically establish record types, fields, and structural relationships. Additionally, the DML defines views of the database.

Question 80

The data definition language (DDL) is able to specify different views of a database. Views restrict the portion of the database that may be used or accessed by different users and programs.