Chapter 4 Flashcards
a set of interrelated, centrally coordinated data files that are stored with as little data redundancy as possible
database
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
database system
analyzing large amounts of data for strategic decision making
business intelligence
using queries to investigate hypothesized relationships among data
online analytical processing (OLAP)
using sophisticated statistical analysis to “discover” unhypothesized relationships in the data.
data mining
document that shows the items stored in a file, including the order and length of the data fields and the type of data stored.
record layout
How people conceptually organize, view, and understand the relationships among data items
logical view
the way data are physically arranged and stored in the computer system
physical view
a description of the data elements in a database, the relationships among them, and the logical model used to organize and describe the data
schema
the organization wide view of the entire database that lists all data elements and the relationships between them
conceptual level schema
an individual user’s view of portions of a database also called a subschema.
external level schema
a subset of the schema; the way the user defies the data and the data relationships
subschema
a low level view of the entire database describing how the data are actually stored and accessed.
internal level schema
information about the structure of the database, including a description of each data element
data dictionary
DBMS language that builds the data dictionary, creates the database, describes logical views, and specifies record of field security constraints
data definition language (DDL)
DBMS language that changes database content, including data element creations, updates, insertions, and deletions
data manipulation language (DML)
high level, english like, DBMS language that contains powerful, easy to use commands that enable users to retrieve sort, order, and display data.
data query language (DQL)
DBMS language that simplifies report creation
report writer
an abstract representation of database contents.
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.
relational data model
a row in a table that contains data about a specific item in a database table
tuple
database attribute, or combination of attributes, that uniquely identifies each row in a table
primary key
an attribute in a table that is also a primary key in another table; used to link the two tables
foreign key
improper database organization where a non primary key item is stored multiple ties; updating the item in one location and not the other causes data inconsistencies.
update anomaly
improper database organization that results in the inability to add record to a database
insert anomaly
improper organization of a database that results in the loss of all information about an entity when a row is deleted.
delete anomaly
a non null primary key ensures that every row i a table represents something and that it can be identified
entity 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
referential integrity rule
following relational database creating rules to design a relational database that is free from delete, insert, and update anomalies
normalization
using knowledge of business processes and information needs to create a diagram that shows what to include in a fully normalized database
semantic data modeling
