L4 Database Management System(DBMS)

Possible database Organizations

1: Files 2: Spreadsheets 3: DBMS

4 types of DBMS

1: Hierarchical 2: Network 3: Relational 4: Object Oriented DBMS

Give an Example of databases:

1: Accounts database 2: Payroll database 3: Amazon's product database 5: Airline reservation database

Database Functionality are?

1: Create/store large datasets 2: Search/query/update 3: Change the structure 4: Concurrent access to many users 5: Recover from crashes 6: Security( not here, but in other apps)

Define a desktop database systems

1: Have one application. 2: Have only a few tables. 3: Are simple in design 4: Involve only one computer. 5: Support one user at a time.

Data Redundancy

1: Inconsistency in data format. 2: the same information may be kept in several different place(files). 3: Data inconsistency which means various copies of the same data are conflicting; waste storage space and duplication of efforts.

Example Organizational DBMS Products

1: MySQL 2: Oracle's Oracle 3: Microsoft's SQL Server 4: IBM's DB2 5: Intersystems Cache

Define the characteristics of a Database Management System(DBMS)

1: Serves an an intermediary between database applications and the database. 2: The DBMS manages and controls database activities. 3: The DBMS creates, processes and administers the databases it controls.

Define Organizational Database System

1: Support several users simultaneously. 2: Include more than one application. 3: Involve multiple computers 4: Are complex in design 5: Have many tables 6: Have many databases

What does a user of a database system do

1: Use a database application to track things. 2: Use forms to enter, read, delete and query data. 3: Produce repots.

What are the four components of a database system?

1: Users 2: Database Application 3: Database Management System(DBMS) 4:Database

What defines a database?

1: a database is a self-describing collection of related records. 2: Self-describing: A database itself contains the definition of its structure. 3:Metadata: is data describing the structure of the database data. 4: Tables within a relational database are related to each other.

What does a Database Application do?

1: create and process forms. 2: Process user queries 3: Create and Process reports 4: Execute application logic 5: Control database applications

SQL to create and populate tables

CREATE TABLE Actors( Name CHAR(30) DateofBirth CHAR(20) ) INSERT INTO Actors VALUES('Tom Hanks',...)

Examples of Desktop DBMS products

Microsoft Access

Searching/Querying/Updating-Find all movies by 'Coppola'

Select title From Movies, Directors, Movie_Directors Where Directors.lname = 'Coppola' and Movies.mid = Movie_Directors.mid and Movie_Directors.id = Directors.id

Database Management System(DBMS)

is a collection of programs that enables users to create, maintain database and control all the access to the database. *The primary goal of the DBMS is to provide an environment that is both convenient and efficient for user to retrive and store information.

Relational DBMS

relation of form of tables: have predefined data types. EX: MySql Oracle, Microsoft SQL Server.

Object Oriented Relation DBMS

storage of new data types: the data to be stored in form of objects, methods to do with the data.

Data Isolation

applications cannot access data associated with other applications

Network DBMS

supports many-to many relationship.

Define a database Applications

1: A database application is a set of one or more computer programs that serves as an intermediary between the user and the DBMS.

What is a database?

A collection of files storing related data.

Transactions have the ACID Properties:

A=Atomicity C= Consistency I= Isolation D= Durability

Hierarchical

Employs the parent child relationship of storing data. Structure of nodes represent records, Branches representing fields. EX: Windows registry configuration settings set up as tree structures with nodes.

Durability

Once a transaction has been committed, it will remain so, even in the event of power loss, crashes, or errors.

Atomicity

Requires that each transaction be "all or nothing": if one part of the transaction fails, then the entire transaction fails, and the database state is left unchanged.