Chapter 12- Databases and Database Management Systems

Attribute

A characteristic of an entity

Database (DB)

A collection of related data that is stored in a manner enabling information to be retrieved as needed; a relational database consists of a collection of related tables

Record

A collection of related fields in a database table.

Multiuser Database system

A database designed to be accessed by multiple users

Single-user database system

A database located on a single computer and designed to be accessed by a single user.

Centralized Database System

A database system in which all of the data used by the system is located on a single computer, such as a server or mainframe computer

Distributed Database System

A database system in which the data used by the system is located on multiple computers that are connected via a network

Client-server database system

A database system where the database is located on a server and accessed by client devices. The client software is also called the front-end and the server the back-end

Hybrid Database

A database that is a combination of two or more database types or models

In-memory database (IMDB)

A database that stores all data in memory instead of on a storage medium; also called a main memory database (MMDB)

Cloud Database

A database, typically hosted on a cloud database provider's server, that is accessible to users via the internet

Column

A field in a database

Flat file

A flat file refers to data files that contain records with no structured relationships. Flat files may contain only basic formatting and have a small, fixed number of fields

Report

A formatted means of looking at a database table or the results of a query. An object used to view or print data. It can be generated from one or more tables and/or one or more queries.

Form

A formatted way of viewing and editing table data in a database. An object used to view, modify or add data to a table. It can be generated from one or more tables and/or one or more queries

Direct Organization

A method of arranging data on a storage medium that uses hashing to specify the exact storage location

Indexed organization

A method of organizing data on a storage medium or in a database that uses an index to specify the exact storage location

Structured Query Language (SQL)

A popular query language standard for information retrieval in relational databases.

Input Mask

A property assigned to a field to specify the format (letters, numbers symbols, etc) that are entered into a field. For example, an input mask for a phone number might be xxx-xxx-xxxx or (xxx) xxx-xxxx

Access

A relational database marketed by Microsoft often used on desktop computers

Query

A request to retrieve information from a database table or tables that matches specific criteria. A query extracts information from a database by specifying particular conditions (called criteria) about the data you would like to retrieve. A query can be created with SQL, a wizard, query by example, or query design. A query is an object that can be used to view data, or modify or add data to a table or tables It can be generated from one or more tables and/or one or more queries.

Field

A single category of data to be stored in a database table, such as a person's name or telephone number

Index

A small table containing a primary key and the location of the record belonging to that key; used to quickly locate records in a database

Primary Key

A specific field in a database table whose value uniquely identifies the records in that table. A primary key is the field in a table that is used to relate that table to other tables

NoSQL

A term that refers to a wide variety of different database technologies that were developed in order to overcome some of the limitations of relational databases

Multidimensional Database (MDDB)

A type of database designed to be used with data warehousing. A MDDB is designed to store a collection of summarized data for quick and easy analysis

Relational Database Management System (RDBMS)

A type of database system in which data is stored in tables related by common fields; the most widely used database model today.

Object-Oriented Database Management System (OODBMS)

A type of database system in which multiple types of data are stored as objects along with their related code

Hybrid XML/ relational database

A type of database system that can store and retrieve both XML data and relational data

ASP (Active Server Pages)

A type of middleware connecting the web server and the database. ASPs are written in JavaScript or VBscript

Database Management System (DBMS)

A type of software program used to create, maintain, and access database

Wizard

A wizard is a series of screens each requesting information to help complete a task such as building a query, form, or report. Wizards are tools built into a DBMS.

Metadata

Data about data, such as the data contained in a data dictionary.

Database developers

Database developers create a database, based on the design generated by the database designer, and prepare it for data entry and access

Data Migration

If a new database is to contain existing data, the data needs to be transferred from old files to the new system, a process called data migration

Table

In a relational database, a collection of related records. An object.

Data security

Protecting the data located in a database against unauthorized access, destruction or misuse

Data privacy

Protecting the privacy of the data located in a database. This is a major concern today

Database model

Refers to the type of database such as hierarchical DB, network DB, relational DB, object-oriented DB, multidimensional DB, etc

Scripts

Short sections of code written in a programming or scripting language that are executed by another program. Middleware for cloud database applications are written as scripts.

Middleware

Software used to connect two otherwise separate applications, such as a web server and a database management system. It converts the request entered into a browser into a database query and passes it on to the database server. Middleware for cloud database applications are written as scripts

Entity

Something (such as a person, an object, or an event) that is important to a business or an organization; typically becomes a database table in a database system for that business or organization

Data integrity

The accuracy or "cleanliness" of data

Characteristics of an OODBMS

The key characteristics for an OODBMS (object orientated DBMS) include object, attributed, methods, classes, and inheritance. They are similar to the object-oriented programming principles

Data definition

The process of describing the characteristics of data that is included in a database table. Characteristics include field name, data type, field size, format, caption, default value, input mask, validation rules, etc

Data validation

The process of ensuring that data entered into a database matches the constraints of the data definition

Normalization

The process of evaluating and correcting the structure of a database table to minimize data redundancy

Data Dictionary

The repository of all data definitions in a database. It includes table structures, security information, relationships between tables in the database, etc.