Chapter 1: Database Management

Database

its purpose is to help people keep track of things of interest to them

Tables

Data is stored here, they have rows and columns like a spreadsheet

instance

Each row in a table stores data about an occurrence or of the thing of interest

Data

facts and objects, for example, student names, email addresses, grade, images, sound etc.

Information

data processed in such a way it can increase the knowledge of the person who is using it

Transactional Data

• Data change

• Relational Database

Historical Data

• Read only data

• Periodically updated in a batch

• Data warehouse

relational database

stores data in tables. A table holds data about one and only one theme. stores data and relationships.

Redundancy and multiple themes create modification problems

• Update problem

• Deletion problem

• Insertion problem

Structured Query Language

is an international standard for creating, processing and querying databases and their tables

The four components of a database system are

• Users

• Database application

• Database Management system (DBMS)

• Database

The four components of a database system are:

Users, database application, database management system (DBMS), Database

Desktop DBMS

User to Database application, to database management system (DBMS), to database

A user of a database system will track

• Use a database application to track things

• Use forms to enter, read, delete and query data

• Produce reports

The database

• A database is a self describing collection of related records

• Self-describing: the database itself contains the descriptions of its structure

• Metadata is data describing the structure of the database, e.g., the names of the columns and the tables to which they belong to, properties of tables and columns, etc

• Tables are related to each other

Database contents

• user data

• metadata

• indexes and other overhead data

• application metadata

Database management system (DBMS)

• it serves as an intermediary between database applications and the database

• The DBMS manages and controls database activities

• The DBMS creates, processes and administers the databases

Functions of a DBMS

• Create databases

• Create tables

• Create supporting structures like indexes

• Read database data

• Modify database data (insert, update, delete)

• Maintain database structures

• Enforce constraints (or rules)

• Control currency

• Provide security

• Perform backup and recovery

Referential integrity constraints

• the DBMS will enforce many constraints or rules

• it ensures that the values of a column in one table is valid based on the values in another table

Database application

is a set of computer programs that serves as an intermediary between the user and the DBMS

Functions of Database Applications

• Create and process forms

• Process user queries

• Create and process reports

• Execute application logic

• Control database applications

What do database Management systems contain?

they typically have:

• a few tables

• are simple in design

• involve only one computer

• support one user at a time

Enterprise-Class (Organizational) DBMS

they typically:

• Support several user simultaneously

• include more than one application

• involve multiple computers

• Are complex in design

• Have many tables

• Have many databases

What is a NoSQL Database?

• NoSQL database= non-relational databasse

• Web 2.0 Applications: Facebook, Twitter, Pinterest

• Apache Software Foundation Cassandra: Facebook, Twitter

Commercial DBMS products

• EX Desktop DBMS products: Microsoft Access

• EX Organizational DBMS products: Microsoft’s SQL server, Oracle’s oracle, Oracle’s MySQL

• IBM’s DB2