Chapter 7 Storing Organizational Information Flashcards
database management system (DBMS)
A database management system (DBMS) creates, reads, updates, and deletes data in a database while controlling access and security. Managers send requests to the DBMS, and the DBMS performs the actual manipulation of the data in the database.
There are two primary tools available for retrieving information from a DBMS.
First is a query-by-example (QBE) tool that helps users graphically design the answer to a question against a database. Second is a structured query language (SQL) that asks users to write lines of code to answer questions against a database. Managers typically interact with QBE tools, and MIS professionals have the skills required to code SQL.
data elementsとdata modelsとは
A data element (or data field) is the smallest or basic unit of information. Data elements can include a customer’s name, address, email, discount rate, preferred shipping method, product name, quantity ordered, and so on. Data models are logical data structures that detail the relationships among data elements using graphics or pictures.
Metadataとは
Metadata provides details about data. For example, metadata for an image could include its size, resolution, and date created.
Data dictionaryとは
A data dictionary compiles all of the metadata about the data elements in the data model. Looking at a data model along with reviewing the data dictionary provides tremendous insight into the database’s functions, purpose, and business rules.
Relational database modelとRelational database management systemとは
relational database model stores information in the form of logically related two-dimensional tables. A relational database management system allows users to create, read, update, and delete data in a relational database. Although the hierarchical and network models are important, this text focuses only on the relational database model.
entity/attributes/record/primary key/foreign keyとは
An entity (also referred to as a table) stores information about a person, place, thing, transaction, or event.
Attributes (also called columns or fields) are the data elements associated with an entity.
A record is a collection of related data elements.
A primary key is a field (or group of fields) that uniquely identifies a given record in a table.
A foreign key is a primary key of one table that appears as an attribute in another table and acts to provide a logical relationship between the two tables.
Information redundancyとは
Information redundancy（過剰、余分）is the duplication of data, or the storage of the same data in multiple places. Redundant data can cause storage issues along with data integrity issues, making it difficult to determine which values are the most current or most accurate.
Information integrityとIntegrity constraintsとは
Information integrity is a measure of the quality of information. Integrity constraints are rules that help ensure the quality of information.
There are two types of integrity constraints:
Relational integrity constraints are rules that enforce basic and fundamental information-based constraints. For example, a relational integrity constraint would not allow someone to create an order for a nonexistent customer, provide a markup percentage that was negative, or order zero pounds of raw materials from a supplier.
A business rule defines how a company performs certain aspects of its business and typically results in either a yes/no or true/false answer. Stating that merchandise returns are allowed within 10 days of purchase is an example of a business rule. Business-critical integrity constraints enforce business rules vital to an organization’s success and often require more insight and knowledge than relational integrity constraints. Consider a supplier of fresh produce to large grocery chains such as Kroger. The supplier might implement a business-critical integrity constraint stating that no product returns are accepted after 15 days past delivery. That would make sense because of the chance of spoilage of the produce. Business-critical integrity constraints tend to mirror the very rules by which an organization achieves success.
Explain the business benefits of a data-driven website.
A data-driven website is an interactive website kept constantly updated and relevant to the needs of its customers using a database.
Additional data-driven website advantages include:
- Easy to manage content: Website owners can make changes without relying on MIS professionals; users can update a data-driven website with little or no training.
- Easy to store large amounts of data: Data-driven websites can keep large volumes of information organized. Website owners can use templates to implement changes for layouts, navigation, or website structure. This improves website reliability, scalability, and performance.
- Easy to eliminate human errors: Data-driven websites trap data-entry errors, eliminating inconsistencies while ensuring all information is entered correctly.
Explain why an organization would want to integrate(まとめる） its databases.
An integration allows separate systems to communicate directly with each other.
Without integrations, an organization will (1) spend considerable time entering the same information in multiple systems and (2) suffer from the low quality and inconsistency typically embedded in redundant information.
