DataBasesDataBasesCourse 1 Course 1

INTRODUCTIONINTRODUCTIONHistory of Databases and History of Databases and

Fundamental NotionsFundamental Notions

Delia-Alexandrina Mitrea, S.L. Eng., PhDE-mail: Delia.Mitrea@cs.utcluj.ro

“ Interviewing Dr. Edgar F. Codd about databases is a bit like interviewing Einstein about nuclear

physics.”

DataBases course

2 hours - Course, 2 hours - Laboratory work

14 weeks Laboratory assessment & exam

3 hour exam, only if P ≥ 5

N = 0,65 * Exam. + 0,35 * Lab.

Passing if N ≥ 5, E ≥ 5, L ≥ 5 & know SQL

Main topics of the discipline

Fundamental notions and the history of databases The database management system (DBMS) Data models

General concepts Relational databases

Relational data manipulation languages (DML)o Relational algebra, relational calculus, QBE (Query By Example)

language o SQL language: SQL SELECT queries, insert, update and delete

operations, SQL data definition language, table creation, view creation, index creation

Data (relations) normalization The PHP language. Creating dynamic web-sites New trends in the development of the databases

Course materials

Baritiu, room H11, database course – Thursday 18.00 – 20.00

Database laboratory –Wednesday• Observator, room 214, 8.00-16.00

PowerPoint course notes The laboratory guide:

http://users.utcluj.ro/~dmitrea/Pagina_persDM/labs/DB_Laboratory.pdf

Course textbooks

R. Ramakrishnan, J. Gehrke, Database Management Systems, McGraw Hill, 2007

R. Dollinger, Baze de Date si Gestiunea Tranzactiilor, Ed. Albastra 1998

R. Dollinger, Utilizarea sistemului SQL Server (SQL 7.0, SQL 2000) Ed. Albastra 2001

Sqlzoo.net (http://www.sqlzoo.net) SQL Server 2008 documentation - SQL Server 2008

Books Online (Microsoft SQL Server 2008 package, on the computer), http://msdn2.microsoft.com/en-us/sql/

Joe Celko, “Joe Celko’s data and databases concepts in practice” http://phoenixalley.com/ebooks/Database and SQL/Celko Data and Databases Concepts in Practice (Morgan, 1999).pdf

R. Riordan, Designing Effective User Interface for Database Systems, Addison Wesley 2005

Ryan K. Stephens, Ronald Plew, Bryan Morgan, Jeff Perkins - QUE - Teach Yourself SQL in 21 Days

Philip Greenspun - SQL for Web Nerds

Course textbooks

Purpose of this discipline

Define an organized collection of data in an optimum manner <=> a database =>• consistency• easy and fast access to the data• comprehensibility• no redundancy• minimum storage space

Useful • in order to store the data of various activity domains• in order to build dynamic web-sites• in order to build environments for technological design • in order to store large and very large amounts of data for automatic decision making

design and implement a database ;use a database management system for application

present introduction to databases and database management systems organize information in DBMS retrieve it efficiently

concentrates on relational systems, which are the dominant type of DBMS

Purpose of this discipline

design a database Structured Query Language (SQL) use a database management system for

application Microsoft SQL Server PHP Web Database application MySQL

Purpose of this discipline

The history of databasesThe history of databases

What is a database?

History:a. How did the databases appear? First forms of data registration: Sumerian small clay tables - 6000 years ago (taxes and levies paid to the local authorities, registration of some judge decisions and sentences) Library appearance, from the antiquity period (the oldest: the Alexandria/Egipt library)

A database consists of an organized collection of data for one or more uses, typically in digital form.

• Data registration in manually designed tables, on various supports (leather, papyrus, paper) – a first form of data systematization/restructuring

• The appearance and development of the computation technologies transposition on the computer, in electronic format, of every manual techniques, represents a qualitative jump, without precedent, concerning the data organization and manipulation; allows a larger amount of data to be stored, in short time and in more complex structures; this data is lot more portable

The history of databasesThe history of databases

In 1960 – IBM developed the Information Management System (IMS) used today in many major installations; the hierarchical data model

the SABRE System, for making airline reservations was jointly developed by American Airlines and IBM around the same time

In 1970 – Edgar Codd proposed a new data representation framework called the relational data model

In 1980 – the relational model consolidated its position as the dominant DBMS paradigm; the SQL query language developed as part of the IBM’s System R project becoming the standard query language; SQL – standardized in 1980 and the current standard SQL-92 was adopted by the American National Standards Institute (ANSI) and International Standards Organization (ISO)

b. How did the databases develop?

The history of databasesThe history of databases

In the late 1980 and during the years 1990 – advances in many areas of database systems: multimedia databases; data warehouses; more powerful query languages and richer data models appeared;

1998 – Carlo Strozzi used the term NoSQL - the open-source relational databases that did not expose the standard SQL• NoSQL databases - less constrained consistency

models than traditional relational databases; • used mainly in big data applications and real-

time web applications

Nowadays period(1):

• Modern databases:

-Variety of domains : for which the data is being registered: socio-economical, scientific, cultural, administration, education, medical, techniques, etc.

-Variety of data registration forms : numerical values, texts, images (static/dynamic), charts etc MultiMedia databases

-Variety of types and architectures : conceived and implemented for the data storage/access - local storage/access, in client-server manner, distributed databases, web accessible databases, large and very large databases, hosted on high performance computers (HPC)

The history of databasesThe history of databases

Model simply cannot put the real world into computer

(or even into your own head ) model has to reflect the things that you

consider important in the real world; the entities and properties that you wish to manipulate and to predict

separate formal model and reality - acknowledge that we cannot capture

everything about reality - so we pick a subset of reality and map it

onto formal operations that we can handle

How do we represent the real world?

Assumptions about reality

•Abstractization: separate relevant aspects from the irrelevant ones

• you have to start somewhere and with some set of primitive concepts to be able to build any model

Primitive concepts - Database Design

• Entities• Attributes• Values• Relationships

Set of primitives

• smaller the set of primitives

-better a mathematician feels-better for an implemen-ter who has to turn the real world into computer

Fundamental Notions (1): (b)DataData versus InformationInformation

•DECISIONS – always necessary, both in the everyday life, and within the special sectors of the various activity domains (socio-economical, cultural, administrative etc)•DECISION making in optimal manner is conditioned by the existence of the INFORMATION concerning the context in which and for which the decisions are being made•THE INFORMATION is obtained through the processing of the DATA specific to the considered domain/context in which and for which the decisions are being made

Data & Information conceptsData & Information concepts

D E C I S I O N S

I N F O R M A T I O N

D A T AD A T A

processing

Data & Information conceptsData & Information concepts

Fundamental notions(2): (b)DataData versus InformationInformation

DEFINITIONS:DEFINITIONS:

1.DATA = facts/objects represented according to some conventions, gathered from the real life through observations and measurements

2. INFORMATION = the result of the data interpretation by a certain subject, that gets the capacity of making decisions

DATA are transposed into INFORMATION only after they are processed through interaction with a system capable of interpreting them

Data & Information conceptsData & Information concepts

CHARACTERISTICS:CHARACTERISTICS:

Obs1:The same DATA can be interpreted in different

manners by different subjects => it can generate different INFORMATION according to the subject/system that processes it

Obs2:DATA – have an objectiv characterINFORMATION – has a subjectiv character. The importance of the appropriate data importance of the appropriate data

registration and management registration and management as objective as objective entities, situated at the decision basisentities, situated at the decision basis

Data & Information conceptsData & Information concepts

Databases

Database Definition Database Management Systems (DBMS) Database Applications

Database Definition

database - collection of data, typically describing the activities of one or more related organizations

database management system, or DBMS, software designed to assist in maintaining and utilizing large collections of data

need for such systems, as well as their use, is growing rapidly

Database: Functional Definition

Database is a stored data collection having the following characteristics:

assures data independence assures access (possibly shared access) to

large volumes of data

Database

university database might contain information about: Entities such as students, faculty, courses, and

classrooms Relationships between entities, such as

students' enrollment in courses, faculty teaching courses, and the use of rooms for courses

Database Need

amount of information available exploding value of data as organizational asset is widely

recognized ability to manage this vast amount of data quickly find information relevant

need for increasingly powerful and flexible data management systems

Database management system (DBMS)

computer program used to manage and query a database

usually categorized according to the data model that they support: hierarchical, network, relational, object

Database management system – data model

data model will tend to determine the query languages that are available to access the database

great deal of the internal engineering of a DBMS is independent of the data model, and is concerned with managing factors such as performance, concurrency, integrity, and recovery from hardware failures

All DBMS performs 3 main functions data definition data manipulation user interface

many other functions that can be carried out data security data integrity data access sharing; data acces control data recovery

Database management system (DBMS)

DataBase Management System, or DBMS

software designed to assist in maintaining and utilizing large collections of data

alternative to using a DBMS is to use ad hoc approaches that do not carry over from one application to another store data in files and write application-specific

code to manage it

Database Importance

there doesn’t exist real applications without a kind of database

great number of DBMS packages can be found on software market, for all types of computers and processing technologies

DBMS can be found at the top 3 of most needed, requested, sold and used products

Database application Common interface between

language, technology and database SQL – Structured Query Language

Architecture Mainframe Client – Server N – Tier Web application

Database Web application

Thank you for your attention!