DATABASE SYSTEM - MELJUN

DATABASE SYSTEM MELJUN CORTES

W e A re L earning T oday
To recognize what a database is and identify where one might be used in and out of school.
To reconize the meaning of key database terms such as Table, Record, Field, Form, Report and Q uery .
To understand what querying a database is.
Understanding Basic Database concepts
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DATA ORGANIZATION CHARACTER is the basic building block of DATA which consist of upper & lower case letter numeric digit (0, 1, 2, etc.) or special character (-, +, -). CHARACTER are put together to form a FACT . FACT are called Field, Item, Word, or String of Character. FACT – a number, a name, or a combination of Character. RECORD – a collection of related FACTS. Example: 1.) Employee Record – it is collection of FACT about one employee. 2.) It indicates name, address, phone #, pay rate, earning made to date & so on. MELJUN CORTES

FILE – is a collection of related RECORD . Example: 1.) A collection of all employee record for one company would be an Employee File . 2.) Inventory File – collection of all inventory record for a particular company or organization. DATA ORGANIZATION Student ID# : 034456 Student Name : MELJUN CORTES Course : BSCS – 4 Birthday : October 2, 1975 Zodiac Sign : Libra Student ID# : 034456 Student Name : MELJUN CORTES Course : BSCS – 4 Birthday : October 2, 1975 Zodiac Sign : Libra Student ID# : 034456 Student Name : MELJUN CORTES Course : BSCS – 4 Birthday : October 2, 1975 Zodiac Sign : Libra FILE RECORD MELJUN CORTES

DATA ORGANIZATION HIERARCHY OF DATA : CHARACTER – are combined to make a Fact. FACT – are combined to make Record. RECORD – are combined to make File. FILE – are combined to make DataBase DataBase File Record Fact Character Note: The Heart of most Organization is DATA . DataBase – is a collection of integrated & related master file . Note: A data base is used as the raw material or input data for all of the application system perform by the organization. MELJUN CORTES

DATABASE SYSTEM MELJUN CORTES Each ROW is a RECORD. Each COLUMN is a FIELD. COLUMN TITLES are FIELD NAME. The type of DATA stored in a FIELD is a FIELD TYPE. The number of CHARACTER in a FIELD is its FIELD WIDTH. A DATABASE is composed of one or more TABLE. A DATABASE is a FILE which is created in automated DBMS SOFTWARE. FIELD NAME RECORD RECORD RECORD RECORD TABLE 10,500 SAM MELBY Jan. 14,2010 104 89,500 MARTIN RIVERA Nov. 15,2009 103 78,452 PIOLO PASCAUL Dec. 12, 2009 102 12,500 MELJUN CORTES Oct 30, 2009 101 Amount Customer Date Number

MELJUN CORTES DATABASE SYSTEM
EXAMPLE OF DATABASE STRUCTURE:
Structure for Database :C:STLMASTER.dbf
Number of Data Records : 268 records
Date of last update : 10/26/1996
Filename of DATABASE FILE : STLMASTER.dbf
Field Field Name Field Data Types Field Width Dec Index
AppNumber character 6
AppDate date 8
Name character 20
Address character 30
LoanAmount numeric 12 2
Rebate numeric 7 2
Interest numeric 7 2
Balance numeric 12 2
Penalty numeric 7 2

DATA ORGANIZATION DATA – is a raw materials or input to any data processing system . - is considered as INPUT DATA. - is manipulated to provide OUTPUT DATA. Example: Student Admission Form & Enrollment Form Pay Slip of an employee INFORMATION – when this OUTPUT DATA can be used to help people make economic decision making. DATA PROCESSING – is that procedures of transforming INPUT DATA into desired OUTPUT DATA. MELJUN CORTES

DATA ORGANIZATION INFORMATION PROCESSING – a special case of data processing is the procedure of transforming data into information which can be used to make better decision . Data Processing System – includes all people, procedures & computer device used to produce desirable output or meaningful information. Information Processing System – includes all people, procedures, computer devices used to procedure useful that can be used in decision making MELJUN CORTES

DATA ORGANIZATION Overview of DATA Processing Ex. Payroll System INPUT PROCESSING OUTPUT Example: 1.) Pay Rate 2.) Hours Worked 3.) Payroll Deduction Example: 1.) Classifying 2.) Sorting 3.) Calculating 4.) Storing 5.) Summarizing 6.) Reproducing Example: 1.) Pay Slip 2.) Payroll Report MELJUN CORTES

INFORMATION SYSTEM Hardware , Software , People , Procedures , Policies , DATA are combined to create an INFORMATION SYSTEM . The term INFORMATION SYSTEM is a generic reference to a Computer-Based System that provides the following: 1.) DATA PROCESSING – capabilities for a company . - DATA PROCESSING capability refers to the System’s ability to handle and process DATA . 2.) INFORMATION SYSTEM – people need to make better more informed Decisions. - The more sophisticated INFORMATION SYSTEMS provide Decision Makers with ON-DEMAND REPORTS and INQUIRY CAPABILITIES as well as routine periodic reports . MELJUN CORTES

Database Concepts Data vs.Information DBMS DATABASE SYSTEM MELJUN CORTES

Database
Computerized Record Keeping System
Collection of Data used by an organization to
Record its Operations
Support Decision Making
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Data
Raw facts and figures
Can be of type
Text
Number
Sound, Image, Chart, Video

Information
Processed Data
Used for Decision Making
Data is also INFORMATION
Information creates DATA

AppDate date 8
Name character 20
Rebate numeric 7 2
Penalty numeric 7 2

A DataBase Management System (DBMS) often just called ‘Database Software’ Sources Documents Like: Enrollment Forms Printed Documents Like: Assessment Forms MELJUN CORTES Input Processing Output Storing Querying Sorting FORMS REPORTS

Database Terminology An organised collection (or Store) of data. A collection of related records , such as all the pupil records in a class. A collection of related fields , such as a pupil’s record. An individual data item, such as Firstname or Date of Birth . Type of information in a field such as text , numeric , date and boolean (Yes/No) MELJUN CORTES Term Meaning Database Table Record Field Data Type

The Russian Doll Analogy Fields inside of… A Database Tables inside of… Records inside of… Data inside of… MELJUN CORTES DATABASE SYSTEM

AppDate date 8
Name character 20
Rebate numeric 7 2
Penalty numeric 7 2

What is a DBMS ? A collection of computer programs that allow storage , modification , and extraction of information from a database . There are many different types of DBMS ranging from small systems that run on personal computers to huge systems that run on mainframes. Examples-- Computerized library systems , automated teller machines, flight reservation systems, computerized parts inventory systems . MELJUN CORTES DATABASE SYSTEM

Introduction To DBMS Concepts MELJUN CORTES DATABASE SYSTEM

What is a DBMS ? A collection of computer programs that allow storage , modification , and extraction of information from a database . There are many different types of DBMS ranging from small systems that run on personal computers to huge systems that run on mainframes. Examples-- Computerized library systems , automated teller machines, flight reservation systems, computerized parts inventory systems . MELJUN CORTES DATABASE SYSTEM

Examples of DATABASE(1)
Admission System
Examination System
Library System
Payroll & Personnel Management System
Accounting System
Hotel Reservation System
Airline Reservation System

Examples of DATABASE (2)
Patient Recording System
Inventory System
Sales and Purchase and Accounting System
Enrollment System
Knowledge-Based Management System
Every Government, Military, Private and other organizations plus Individual can make use of DB

Data Management
Manual Filing System
Computerized Filing System
Database Systems

Filing System
Every Department/Company has its own
Data File(s)
Application to Maintain Data File(s)
-- Computerized Data Maintenance System

Library System - Example Members Catalog Register Members Management Application Catalog Management Application Transaction Management Application Lists of All Members, New Members, Joins between specified Dates. etc Lists of All Books, New Books, Issued Books, Lost Books,. etc Books Issued Today, Books Receipt Today, etc Files Applications Operations DATABASE SYSTEM MELJUN CORTES

Database System
Single, Central, Large Repository
Shared Resource
Have Logical Connections among data items
DBA is responsible of its design, creation and maintenance
DATABASE SYSTEM MELJUN CORTES Is a PERSON

Library System - Example Members Management Application Catalog Management Application Transaction Management Application Lists of All Members, New Members, Joins between specified Dates. etc Lists of All Books, New Books, Issued Books, Lost Books,. etc Books Issued Today, Books Receipt Today, etc Members Catalog Register DBMS Database DATABASE SYSTEM MELJUN CORTES

DBMS
Software Package that provides
Support to applications system
-- Computerized DATA Handling
User-interface for on-line queries

Advantages of DBMS (1)
Sharing of Data
Control of Redundancy
-(unnecessary wastage of disk space)
Data Consistency
Improvement of Data Standards
Improvement of Data Integrity
-(Intra-record, inter-record, referential)
Balancing of Conflicts
Faster Development of New Applications

Advantages of DBMS (2)
Better Security
Passwords
Encryption
Views and Stored Procedures
Better Data Accessibility
(query language- SQL programming)
Economy of Scale
Transaction handling
Better backup and Recovery Procedures

Disadvantages of DBMS
Higher Costs of
DBMS
Hardware
Conversion
Programming
Slow Processing of Some Applications
More Security Risks
More Difficult Recovery

Kinds of Databases
Relational: Oracle 9i/8i, SQL-Server 2000/7.0/6.5,
Teradata, Sybase(SQL Anywhere),
DB2, Informix
MS-Access, Foxpro 2.6/2.5,dbase IV/3 +
Network e.g. IDS Server
Paradox, FoxBase, Dbase3+, DbaseIV
DBU, Visual FoxPro, MS-Access – Windows 7

Relational DBMS DATABASE SYSTEM TABLE TABLE TABLE TABLE

Important RDBMS Objects
Tables
Views
Triggers
Stored Procedures
Functions
Primary Key
Foreign Key

Networked DBMS MELJUN CORTES DATABASE SYSTEM

SQL : It is an acronym for Structured Query Language. It is the language in which, the client sends the request to the database for data Eg. Select name, address From emp Where city = ‘BUTUAN CITY’ SQL : MELJUN CORTES DATABASE SYSTEM

PL/SQL:
It is an acronym for Programming Language/Structured Query Language
Apart from writing the SQL you also have the programming language constructs like
If then else (checking conditions)
Looping (Executing the set of statements more that once)
Exception and error handling (Taking care of run time errors)

Database Design
Database design is the process of producing a detailed data model of a database. This logical data model contains all the needed logical and physical design choices and physical storage parameters needed to generate a design in a Data Definition Language, which can then be used to create a database. A fully attributed data model contains detailed attributes for each entity.
Process:
Determine the data to be stored in the database
Determine the relationships between the different data elements
Superimpose a logical structure upon the data on the basis of these relationships.

Database Objects A Database Trigger is procedural code that is automatically executed in response to certain events on a particular table in a database. Triggers can restrict access to specific data, perform logging, or audit data modifications. A Database View is a virtual or logical table composed of the result set of a query. Unlike ordinary tables (base tables) in a relational database, a view is not part of the physical schema: it is a dynamic, virtual table computed or collated from data in the database. Changing the data in a table alters the data shown in the view In relational databases , SQL databases, and flat file databases, a Table is a set of data elements (values) that is organized using a model of horizontal rows and vertical columns. MELJUN CORTES DATABASE SYSTEM

In database packages , the term Cursor refers to a control structure for the successive traversal (and potential processing) of records in a result set. A Transaction Log (also database log or binary log) is a history of actions executed by a database management system to guarantee ACID properties over crashes or hardware failures. Physically, a log is a file of updates done to the database, stored in stable storage. A Database Index is a data structure that improves the speed of operations in a table. Indexes can be created using one or more columns, providing the basis for both rapid random lookups and efficient ordering of access to records. A Stored Procedure is a subroutine available to applications accessing a relational database system. Stored procedures (sometimes called a sproc or SP) are actually stored in the database. Database Objects DATABASE SYSTEM MELJUN CORTES

Normalization Why Normalize? Ideally, a relational database table should be designed in such a way as to exclude the possibility of update, insertion, and deletion anomalies. The normal forms of relational database theory provide guidelines for deciding whether a particular design will be vulnerable to such anomalies. It is possible to correct an unnormalized design so as to make it adhere to the demands of the normal forms: this is called normalization. A table that is not sufficiently normalized can suffer from logical inconsistencies of various types, and from anomalies involving data operations causing Update, Insert and Delete Anomalies. MELJUN CORTES DATABASE SYSTEM

TRANSACTION MANAGEMENT
What is a Database Transaction ?
A database transaction is a unit of interaction with a database management system or similar system that is treated in a coherent and reliable way independent of other transactions. In general, a database transaction must be atomic, meaning that it must be either entirely completed or aborted. Ideally, a database system will guarantee the properties of Atomicity, Consistency, Isolation and Durability (ACID) for each transaction.
A Simple Transaction
Begin the transaction
Execute several queries
Commit the transaction

ACID In computer science , ACID (Atomicity, Consistency, Isolation, Durability) is a set of properties that guarantee that database transactions are processed reliably. In the context of databases, a single logical operation on the data is called a transaction. Atomicity - Atomicity refers to the ability of the DBMS to guarantee that either all of the tasks of a transaction are performed or none of them are. Consistency - Consistency refers to the database being in a legal state when the transaction begins and when it ends. This means that a transaction cannot break the rules, or integrity constraints, of the database. Isolation - Isolation refers to the ability of the application to make operations in a transaction appear isolated from all other operations Durability -Durability ensures that the results of a completed transaction are permanent and can survive future system and media failures; that is, once they are done, they can not be undone. DATABASE SYSTEM MELJUN CORTES

Kinds of Database Consultants
DATABASE Designers
is a person
DATABASE Developers
is a person
DBA (Data Base Administrator)
is a person

DATABASE Designers:
These consultants Analyze, design the complete structure of the database.
They design Tables, Views, Normalization, ER Diagram, Integrity constraints, etc.

DATABASE Developers :
These consultant write stored procedures, triggers, functions, etc.
Technical terms found in the resume of such consultants —
Triggers
Stored Procedures
Packages
Unix Shell Scripting

DB ADMINISTRATOR :
These consultants’ profile includes installation, configuration, migration, backup, recovery operations
Various Tasks of the DBA are:
a) Granting access
b) User creation and deletion
c) Performance tuning
d) Query optimization

Related Skills in DATABASE SYSTEM
Data Warehousing
Development of a data warehouse includes development of systems to extract data from operating systems plus installation of a warehouse database system that provides managers flexible access to the data
Data Mining
A class of database applications that look for hidden patterns in a group of data that can be used to predict future behavior
Data Modeling
The analysis of data objects and their relationships to other data objects. Data modeling is often the first step in database design and object-oriented programming as the designers first create a conceptual model of how data items relate to each other. Data modeling involves a progression from conceptual model to logical model to physical schema.
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THE END MELJUN CORTES

DATABASE SYSTEM - MELJUN

by MELJUN CORTES, MBA,MPA on Feb 06, 2010

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DATABASE SYSTEM - MELJUN — Presentation Transcript