AIS Chapter 4

data definition language (DDL)

DBMS language that builds the data dictionary, creates the database, describes logical views, and specifies record or field security constraints

data manipulation language (DML)

DBMS language that changes database content, including data element creations, updates, insertions, and deletions

report writer

DBMS language that simplifies report creation

logical view

How a user conceptually organizes and understands data is referred to as the _______. physical view logical view data model view data organization view

referential integrity rule

The constraint that all foreign keys must have either null values or the value of a primary key in another table is referred to as which of the following? referential integrity rule entity integrity rule foreign key value rule null value rule

entity integrity rule

The constraint that all primary keys must have nonnull data values is referred to as which of the following? referential integrity rule entity integrity rule normalization rule relational data model rule

tables

The relational data model portrays data as being stored in _________. hierarchies tables objects files

tuple

What is each row in a relational database table called? relation attribute anomaly tuple

customer number

Which of the following attributes in the Cash Receipts table (representing payments received from customers) would most likely be a foreign key? cash receipt number customer check number customer number cash receipt date

supplier number

Which of the following attributes would most likely be a primary key? supplier name supplier number supplier zip code supplier account balance

DBMS

Which of the following is a software program that runs a database system? DQL DBMS DML DDL

external-level schema

Which of the following is an individual user's view of the database? conceptual-level schema external-level schema internal-level schema logical-level schema

DQL

Which of the following would managers most likely use to retrieve information about sales during the month of October? DML DSL DDL DQL

relational database

a database built using the relational data model

schema

a description of the data elements in a database, the relationships among them, and the logical model used to organize and describe the data

internal-level schema

a low-level view of the entire database describing how the data are actually stored and accessed

entity integrity rule

a nonnull primary key ensures that every row in a table represents something and that it can be identified

tuple

a row in a table that contains data about a specific item in a database table

database

a set of interrelated, centrally coordinated data files that are stored with as little data redundancy as possible

subschema

a subset of the schema; the way the user defines the data and the data relationships

relational data model

a two-dimensional table representation of data; each row represents a unique entity (record) and each column is a field where record attributes are stored

data model

an abstract representation of database contents

foreign key

an attribute in a table that is also a primary key in another table; used to link the two tables

external-level schema

an individual user's view of portions of a database; also called a subschema

business intelligence

analyzing large amounts of data for strategic decision making

primary key

database attribute, or combination of attributes, that uniquely identifies each row in a table

record layout

document that shows the items stored in a file, including the order and length of the data fields and the type of data stored

normalization

following relational database creation rules to design a relational database that is free from delete, insert, and update anomalies

referential integrity rule

foreign keys which link rows in one table to rows in another table must have values that correspond to the value of a primary key in another table

data query language (DQL)

high-level, English-like, DBMS language that contains powerful, easy-to-use commands that enable users to retrieve, sort, order, and display data

logical view

how people conceptually organize, view and understand the relationships among data items

insert anomaly

improper database organization that results in the inability to add records to a database

update anomaly

improper database organization where a non-primary key item is stored multiple times; updating the item in one location and not the others causes data inconsistencies

delete anomaly

improper organization of a database that results in the loss of all information about an entity when a row is deleted

data dictionary

information about the structure of the database, including a description of each data element

database system

the database, the DBMS, and the application programs that access the database through the DBMS

conceptual-level schema

the organization-wide view of the entire database that lists all data elements and the relationships between them

database administrator

the person responsible for coordinating, controlling, and managing the database

database management system (DBMS)

the program that manages and controls the data and the interfaces between the data and the application programs that use the data stored in the database

physical view

the way data are physically arranged and stored in the computer system

semantic data modeling

using knowledge of business processes and information needs to create a diagram that shows what to include in a fully normalized database (in 3NF)

online analytical processing (OLAP)

using queries to investigate hypothesized relationships among data

data mining

using sophisticated statistical analysis to "discover" unhypothesized relationships in the data

data warehouse

very large databases containing detailed and summarized data for a number of years that are sued for analysis rather than transaction processing