Database Management Systems Chapter 1

Relational Model

All relational database DBMS products are built on this model -E.F. Codd applied the concepts of a branch of math called relational algebra to the problem of databases

Users

Final component of a database system, employ a database application to keep track of things -Use forms to read, enter, query data -produce reports to convey information

Surrogate Key

If the numbers used in primary key columns such as StudentNumber and ClassNumber are automatically generated and assigned in the database itself, then the key is also called the surrogate key

Data Warehouses and Data Marts

Store data specifically organized for research and reporting purposes, and these data are often exported to other analytical tools

SQL helps you produce information from a database

TRUE

SAP is the leading vendor of ERP applications

TRUE a key element of its product is a database that integrates data from various businesses.

Integrated Tables

Tables that store both data and the relationships among the data

e-commerce is an important database application

databases are a key component of e-commerce order entry, billing, shipping, and customer support

Applications that connect to the database over a corporate network

- These applications are called client/server applications because the application program is a client that connects to a database server. -Client/server applications are written in VB.NET, C++, Java

Referential Integrity Constraints

- With most DBMS products, it is possible to declare rules about data values and have a DBMS enforce them. -The rules are called this (RIC)

Database Migration

-A database is adapted to new or changing requirements -In the migration process, tables may be created, modified, or removed; relationships may be altered; data constraints may be changed

Oracle MySQL

-A powerful, open source DBMS frequently chosen for Web applicaitions

Enterprise-class database system

-Database applications in an enterprise-class database system introduce functions and features beyond the basics

The DBMS manages the database.

-It processes SQL statements and provides other features and functions for creating, processing, and administering the database

Information

-Knowledge derived from data -Data presented in a meaningful context -Data processed by summing, ordering, averaging, grouping, comparing, or other similar operations

Data Model

-The development team creates a data model from the requirements statements and then transforms that data model into a database design -A blueprint that is used as a design aid on the way to a database design, which is the basis for constructing the actual database in a DBMS product

A second category of applications is e-commerce and other applications that run of a Web server

-Users connect to such applications via Web browsers such as Internet Explorer. Common web servers include Microsofts Internet Information Server (IIS) and Apache -Common languages for web server applications include PHP, Java, Microsoft .NET languages such as c#.NET and VB.NET

Database System (2)

1. Users 2. The database application 3. SQL 4. The database management system (DBMS) 5. The database

Database Design (2)

1. process of designing a database 2. the annotated diagram that is the result of that process ......term is used both ways, watch out for the context

Concurrecny

A DBMS controls concurrency by ensuring that one user's work does not inappropriately interfere with another user's work

Self-describing

A database is self-describing because it contains a description of itself

Row

A row of a table has data about a particular instance or occurrence of the things of interest

Database Application

A set of one or more computer programs that serves as an intermediary between the user and the DBMS -Frequently written in house (can be acquired from software vendors) -Present data to users in the format of forms or reports

What do database professionals use?

A set of principles, collectively called normalization, or normal forms, to guide and assess database design

PrimaryKey

The values of these keys are used to create the relationships between the tables

Database Design

As a process, is the creation of the proper structure of database tables, the proper relationships between tables, appropriate data constraints, and other structural components of the database

Knowledge Worker

As a user, you prepare reports, mines data, and does other types of data analysis -users concerned with constructing SQL statements to get and put the data they want

Records

Because each row records the data for a specific instance, rows are also know as records

Database

Collection of related tables and other structures

Database Management System (DBMS)

Computer program used to create, process, and administer the database.

Metadata

Databases contain not only tables of user data, but also tables of data that describe that user data -data about data

Database System

Defined to consist of four components: 1. Users 2. The database application 3. The database management system (DBMS) 4. The database

Database Administrator

Designs, constructs, and manages the database itself -Concerned with the management of the database

Column

Each column of a table stores a characteristic common to all rows

The most popular data modeling technique

Entity-relationship (ER) data modeling

Structured Query Language (SQL)

Internationally recognized standard language that is understood by all commercial DBMS products, in database processing, and and the fact that database applications typically send SQL statements to the DBMS for for processing, we can refine our our illustration of a database system.

Personal Database System

Microsoft Access is not just a DBMS; it is a personal database system: a DBMS plus an application generator.

Foreign Key

Provides a link between two tables

Table

Rows and columns, like those in a spreadsheet

Relational Database

The purpose of a database is to help people keep track of things, and the most commonly used type of database is the relational database. -stores data in tables

Databases record facts and figures, so they record data.

They do so, however, in a way that produces information.

A database is a self-describing collection of integrated tables

True

Companies almost never write their own DBMS programs.

True

E-commerce companies use Web activity databases to determine which items on a Web page are popular and successful and which are not.

True

The DBMS receives requests encoded in SQL and translates those requests into actions on the database.

True

Programmer

Writes applications that process the database

Columns

also known as fields

A customer relationship management system (CRM)

an information system that manages customer contacts from initial solicitation through acceptance, purchase, continuing purchase, support, etc -used by sales managers, salespeople, customer service

Enterprise Resource Planning (ERP)

an information system that touches every department in a manufacturing company.

CODASYL DBTG

an unnecessarily complicated model

Data

recorded facts and numbers

What are the largest databases?

the ones that track are those that track customer browser behavior

Data Language/I (DL/I)

the way this program structured data relationships was by using hierarchies and trees

By adding a foreign key,

we create a relationship between the two tables

an example of e-commerce is

www.amazon.com and www.drugstore.com -They keep track of the web pages and the web page components that they send to their customers. they also track customer clicks. additions to shopping carts, order purchases, etc.