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.