315 ch1-2

What is a business rule, and what is its purpose in data modeling?

A business rule is a brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization. These rules are used to help define entities, attributes, relationships, and constraints needed to create a data model.

Define File

A collection of related records. For example, a file might contain data about the students currently enrolled at Gigantic University.

What is a DBMS, and what are its functions?

A database management system (DBMS) is the collection of programs that manages the database structure and controls access to the data stored in the database. A DBMS's functions are as follows: data dictionary management, da; it is important because it ta storage management, data transformation and presentation, security management, multiuser access control, backup and recovery management, data integrity management, database access languages and application programming interfaces, and database communication interfaces.

Define Record

A logically connected set of one or more fields that describes a person, place, or thing. For example, the fields that constitute a record for a customer might consist of the customer's name, address, phone number, date of birth, credit limit, and unpaid balance.

Discuss the importance of data models.

A model's helps in understanding the complexities of the real-world environment, representing data structures and their characteristics, relations, constraints, transformations, and other constructs with the purpose of supporting a specific problem domain.

What is a relational diagram? Give an example.

A relational diagram is a graphical representation of a relational database's entities, the attributes within those entities, and the relationships among the entities.

What is a relationship, and what three types of relationships exist?

A relationship describes an association among entities, and the three types are One-to-many, many-to-many, and one-to-one.

What is a table, and what role does it play in the relational model?

A table is a logical construct perceived to be a two-dimensional structure composed of intersecting rows (entities) and columns (attributes) that represents an entity set in the relational model. A table helps avoid the complexity of abstract mathematical theory and represents a mathematical concept simply.

Explain why the cost of ownership may be lower with a cloud database then with a traditional, company database.

A traditional, company database resides within an organization's network infrastructure, while a cloud database resides on the internet and allows an organization to quickly add database systems to their environment.

What is an ERDM, and what role does it play in the modern (production) database environment?

An ERDM is a model that includes the object-oriented model's best features in an inherently simpler relational database structural environment. This model gave birth to a new generation of relational databases that support object-oriented features such as objects (encapsulated data and their methods), extensible data types based on classes, and inheritance.

What is connectivity? (Use a Crow's Foot ERD to illustrate connectivity.)

Connectivity is the type of relationship between entities. There is a crow foot example in Exercise 6 and 14.

Explain the differences among data, information, and a database.

Data consists of raw facts, while information is the result of processing raw data to reveal its meaning; in respect data and information, a database is a specialized structure that allows computer-based systems to store, manage and retrieve data in a timely manner

What is data independence, and why is it lacking in file systems?

Data independence is a condition in which data access is unaffected by changes in the physical data storage characteristics. It is lacked in file systems because when of any of a file's data storage characteristics is changed, all data access programs are subject to change

What is data redundancy, and which characteristics of the file system lead to it?

Data redundancy is the repetition of data when not needed, and exists when the same data is stored unnecessarily at different places.

Explain why database design is important.

Database design is the process that yields the description of the database structure and determines the database components. Database design is important because a good DBMS relies on the designed database, which is why it must be designed carefully, meeting all requirements by users.

How do you translate business rules into data model components?

In translating business rules into data model components, a noun is translated as an entity, a verb (active or passive) associated with the nouns translates the relationship between the entities, and an adjective translates as an attribute for the associated noun(s).

Explain the significance of the loss of direct, Hands-On access to business data that end users experienced with the Advent of computerized data repositories.

It gave end users the tools to convert business data into the information they needed in order to manipulate it. On the other hand, it introduced a gap between the end users and their data, which then influenced the development of many types of computer technologies, system designs, and uses of many technologies and techniques

What is logical independence?

Logical independence is a condition in which the internal model can be changed without affecting the conceptual model.

What is metadata?

Metadata is data about data characteristics and relationships.

What is physical independence?

Physical independence is a condition in which the physical model can be changed without affecting the internal model.

Define Data

Raw facts, such as a telephone number, a birth date, a customer name, and a year-to-date (YTD) sales value. Data has little meaning unless it has been organized in some logical manner.

What is the role of a DBMS, and what are its advantages? What are its disadvantages?

Role of a DBMS: serves as the intermediary between the user and the database, storing collection(s) of files; receives all application requests request and translates them into the complex operations required to fulfill those requests Advantages: improved data sharing, improved data security, better data integration, minimized data inconsistency, improved data access, improved decision making, and increased end-user productivity Disadvantages: increased costs, management complexity, maintaining currency, vendor dependence, frequent upgrade/replacement cycles

What common problems does a collection of spreadsheets created by end-users share with a typical file system?

Some common problems are lengthy development times, difficulty of getting quick answers, complex system administration, lack of security and limited data sharing, and exclusive programming

What is structural Independence, and why is it important?

Structural dependence is a data characteristic in which changes in the database schema do not affect data access; it is important in the fact that there is the ability to change the file structure without affecting the application's ability to access the data.

Explain how the entity relationship (ER) model helped produce a more structured relational database design environment.

The ER model complemented the relational data model concepts. ER models are typically represented in entity relationships diagrams (ERD), where each row is an entity instance and a collection of entities is an entity set; each entity has a set of attributes, while relationships between entities are labeled in how they are connected (connected relationships could be one-to-many, many-to-many, and one-to-one).

What are the potential costs of implementing a database system?

The costs stem from sophisticated hardware and software, highly skilled personnel required to operate and manage a database system, as well as training, licensing, and regulation compliance costs

What are the main components of a database system?

The main components of a database system are hardware, software, people, procedures, and data.

Describe the basic features of the relational data model and discuss their importance to the end user and the designer.

The relational data model aesthetically is a two-dimensional structured table consisting of rows and columns. Each row in the table is referred as a tuple, while each row represents an attribute that describes the entity. It helps end users and designers alike in the fact that following relationships, entities, and adjectives is cohesive in the relational data model format.

Use examples to compare and contrast unstructured and structured data. Which type is more prevalent in a typical business environment?

Unstructured data is data that exists in its original, raw state; that is, in the format in which it was collected. Structured data is data that has been formatted to facilitate storage, use, and information generation. Unstructured data could be seen as keeping logs of girl scout cookie sales from individual scouts in graphical form, while structured data would be taking data into a spreadsheet to compute important stats such as number of sales per region or troop. Semi-structured data is the most prevalent in a typical business environment.

Define Field

a character or group of characters (alphabetic or numeric) that has a specific meaning. A field is set to define and store data.

Give an example of each of the three types of relationships.

a. One-to-one: Every person has one onecard on campus. b. One-to-many: One person can own multiples credit cards c. Many-to-many: Students can take multiple classes.

What are some basic database functions that a spreadsheet cannot perform?

support for self-documentation through metadata, enforcement of data types or domains to ensure consistency of data within a column, defined relationships among tables, or constraints to ensure consistency of data across related tables

List and describe the different types of databases.

single-user database, desktop database, multiuser database, workgroup database, enterprise database, centralized database, distributed database, cloud database, general-purpose database, discipline-specific database, Operational database, analytical database