Tilley C9 - CNIT182

data structure

Framework for organizing, storing, and managing data

file-oriented system

stores and manages data in one or more separate files

Relational Database/Model

stores information in the form of logically related two-dimensional tables

Database Management System (DBMS)

Collection of programs that enables users to add, update, manage, access, and analyze data

Scalability

the capacity for the system to change in size and scale to meet new demands

economy of scale

The inherent efficiency of high-volume processing on larger computers.

Database Administrator (DBA)

Person who is responsible to maintaining the database and assessing its overall requirements

Data Manipulation Language (DML)

Program that allows for database operations, such as storing, retrieving, updating, and deleting data.

query language

Program that allows a user to specify a task without specifying how it will be completed.

query by example (QBE) language

Program that allows the user to specify a task by providing an example of the data requested.

Structured Query Language (SQL)

Language used to communicate between client workstations and mainframe/server computers

Schema

complete definition of a database, including all of its parts.

Subschema

The actual view of the database, it is defined on the permissions that a particular system or user has.

Open Database Connectivity (ODBC)

protocol that facilitates data transfer between software made by different vendors.

Java Database Connectivity (JDBC)

Enables Java applications to exchange data with any database that uses SQL statements and is JDBC-compliant

Middleware

Software that integrates different applications and allows them to exchange data

entity

A person, place, thing, transaction, or event about which information is stored

table/file

contains a set of related records that store data about a specific entity

Field/Attribute

single characteristic or attribute of anentity

Common Field

Attribute that appears in more than one entity

Record/Tuple

set of related fields that describes one instance, or occurrence, of an entity, such as one customer, one order, or one product

Key Fields

Used to organize, access, and maintain data structures

Primary Key

A field (or group of fields) that uniquely identifies a given entity in a table

Combination/composite/concatenated/multivalued key

data validation check that is performed on two or more fields

Candidate Key

any field that could serve as a primary key

nonkey field

Any field that is not a primary key or a candidate key

Foreign Key

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

Secondary Key

Key used strictly for data retrieval purposes

Referential Integrity

Set of rules that avoids data inconsistency and quality problems

orphan

An unassociated or unrelated record or field. Referential integrity would prevent the creation of this orphan.

Entity Relationship Diagram (ERD)

a model that shows the logical relationships and interaction among system entities

One-to-One Relationship

One entity relates to exactly one entity.

One-to-Many Relationship

One entity relates to multiple instances of another.

Many-to-Many Relationship

One entity can be associated with many other entities and vice versa.

Associative Entity

Event or transaction that links the two entities of a many-to-many relationship, but has its own characteristics

Cardinality

numeric relationship between two entities

Cardinality Notation

UML representation of cardinality

Crow's Foot Notation

A representation of the entity relationship diagram that uses a three-pronged symbol to represent the "many" sides of the relationship.

Normalization

Process of creating table designs by assigning specific fields to each table in the database.

table design

Specifies the fields and identifies the primary key in a particular table or file.

standard notation format

used to show a table's structure, fields, and primary key

repeating group

A set of one or more fields that can occur any number of times in a single record, with each occurrence having different values.

unnormalized

A table design that contains a repeating group

First Normal Form (1NF)

A table that does not contain a repeating group

functionally dependent

An attribute is functionally dependent on another attribute (or a collection of other attributes) if a value for the first attribute determines a single value for the second attribute at any time.

Second Normal Form (2NF)

A relation that is in 1NF and every non-primary key attribute is fully dependent on the primary key.

Third Normal Form (3NF)

A table that is in 2NF and no nonkey field is dependent on another nonkey field

code

a set of letters or numbers that identifies information

sequence code

Numbers or letters assigned in a specific order

block sequence code

Code that uses blocks of numbers for different classifications.

Alphabetic Code

Uses alphabet letters to distinguish one item from another based on a category, an abbreviation, or an easy-to-remember value, called a mnemonic code.

Category Codes

Type of alphabetic code that identifies a group of related items

Abbreviation codes

type of alphabetic code that abbreviates a word (think airports)

Significant digit codes

Distinguish items by using a series of subgroups of digits

Derivation codes

Combine data from different item attributes, or characteristics

Cipher codes

Use a keyword to encode a number

Action codes

Indicates what action is to be taken with an associated item.

Data Warehouse

integrated collection of data that can include unrelated information

Data Mart

a data collection that addresses the needs of a particular department or functional area of the business

Data Mining

software that looks for meaningful data patterns and relationships

clicks to close

average page views to accomplish a task

clickstream storage

Recording web visitor behavior and traffic trends for later data mining use.

Market Basket Analysis

Specific type of data analysis that focuses on the composition of the basket (or bundle) of products purchased by a household during a single shopping occasion.

Logical Storage

Data that a user can view, understand, and access regardless of how it is stored

Physical Storage

Strictly hardware-related

Involves the process of reading and writing binary data to physical media

data element/item

another word for data field

logical record

Set of field values that describes a single person, place, thing, or event

Bits

binary digits (0s and 1s)

EBCDIC

A coding method used on mainframe computers and some high-capacity servers.

ASCII

coding method used on most personal computers

Bytes

8 bits = 1 (?)

binary storage format

A format that offers efficient storage of numeric data.

unicodde

Newer coding standard that uses 2 bytes/character instead of 1

absolute date

the total number of days from some specific base date

permissions

privileges given to a user

encryption

Process of converting readable data into unreadable characters to prevent unauthorized access.

Recovery Procedures

Actions necessary to restore data files of an information system and

computational capability after a system failure.

audit log files

Records details of all accesses and changes to a file or database

Audit Fields

Special fields within data records to provide additional control or security information.