Database fundamentals(database)

ISOM3260 Database Design & Administration

Dr. Muller Cheung (L1/L2)

Dr. James Thong (L3)

Office hour: By appointment

Email: [email protected]; [email protected] 2014

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Today’s Agenda

• Introduction to course– ISOM3260 website: http://teaching.ust.hk/~isom3260– Midterms and Final exam– Group project

• Database Fundamentals (Chap. 1)

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Conduct in Class

• Attend the lab you are enrolled in• Attend the lecture you are enrolled in• Be punctual for lab/lecture• Turn off mobile phones• Do not distract other students or instructor

by talking with your friends

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How to study for ISOM3260

• Attend lectures– Questions in exams will only include topics

covered in lectures• Read the textbook for more information• Review lecture notes/textbook after lecture• Email questions to me or make appointment

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What you will learn from this course• Database fundamentals

– introduction to database concepts• Database development process

– steps to develop a database• Conceptual data modeling

– entity-relationship (ER) diagram; enhanced ER• Logical database design

– transforming ER diagram into relations; normalization• Physical database design

– technical specifications of the database• Database implementation

– Structured Query Language (SQL), advanced SQL• Advanced topic

– data warehousing; data and database administration

Lecture 1: Database Fundamentals

ISOM3260, Spring 2014

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Database Fundamentals

• Concepts• Disadvantages of file processing systems• The database approach• Advantages of database approach• Costs and risks of database approach• Range of database applications• Components of database environment• Evolution of database systems• Current development

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Concepts• Data

– stored representations of meaningful objects and events– structured data: numbers, text, dates– unstructured data: images, video, documents

• Information– data processed to be useful in decision making– by putting data in a context or summarizing data

• Database– an organized collection of logically related data– e.g. automobile repair database contains data on customers,

automobiles, and repair history• Metadata

– data that describes properties of user data

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Figure 1-1a: Data in Context

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Figure 1-1b: Summarized data

Useful information that managers can use for decision making and interpretation

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Table 1-1: Metadata for Class Roster

Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context

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Disadvantages of File Processing• Program-data dependence

– all programs maintain metadata for each file they use– change to file structure requires changes to all programs that

access the file• Data redundancy (duplication of data)

– data changes in one file could cause inconsistencies, compromising data integrity

• Limited data sharing– no centralized control of data

• Lengthy development times– programmers must design their own file formats

• Excessive program maintenance– consume 80% of information systems budget

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Figure 1-2: Old file processing systems at Pine Valley Furniture Company

Duplicate Data

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The Database Approach

Database Management System (DBMS) manages data resources like an operating system manages hardware resources

Databasecontainingcentralizedshared data

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Advantages of Database Approach

• Program-data independence – metadata not stored in programs, so programs do not need to

worry about changes to data formats– results in increased productivity of application development and

reduced program maintenance

• Minimal data redundancy– avoid wasted storage space– leads to increased data integrity/consistency

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Advantages of Database Approach

• Improved data sharing– different users get different views of the data

• Enforcement of standards– naming conventions, data quality standards, and uniform

procedures for accessing, updating, and protecting data• Improved data quality

– constraints are business rules that cannot be violated by database users

– enforced by DBMS• Improved data accessibility and responsiveness

– use of structured query language (SQL)– end users without programming experience can easily retrieve

data

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Costs and Risks of the Database Approach

• Requires new, specialized personnel• Installation and management cost and complexity

– requires new software and upgrades to hardware and data communications

– substantial annual maintenance and support costs• Conversion costs

– converting from legacy systems costs money and time• Need for explicit backup and recovery

– shared corporate database must be accurate and available at all times

• Organizational conflict– agreement on data definitions and ownership, responsibilities

for accurate data maintenance– need strong top management support to resolve

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Figure 1-3: Segment from enterprise data model(shows the high-level entities and their relationships)

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One customer places many orders, but each order is placed by a single customer

One-to-many relationship

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One order contains many order lines; each order line is contained in a single order


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One product can be in many order lines, each order line refers to a single product


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Therefore, one order involves many products and one product is involved in many orders

Many-to-many relationship

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Order, Order_Line, Customer, and Product tables

Relationships established in special columns that provide links between tables

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Range of Database Applications

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Typical data from a personal database on a PC, notebook, smartphone

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Fig. 1-11: Two-Tier Database with Local Area Network

Enterprise Database Applications

• Enterprise Resource Planning (ERP)– business management system that integrates all

enterprise functions (e.g., manufacturing, finance, sales, marketing, inventory, accounting, human resources)

• Data Warehouse– an integrated decision support system derived

from various operational databases

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An enterprise data warehouse

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Components of the Database Environment

• Computer-Aided Software Engineering (CASE) Tools – automated tools used to design databases and application programs

• Repository – centralized storehouse of metadata• DBMS – software for managing the database• Database – storehouse of the data• Application Programs – software using the data• User Interface – text and graphical displays to users• Data/Database Administrators – personnel responsible for

maintaining the database• System Developers – personnel responsible for designing

application programs• End Users – people who use the applications and databases

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Figure 1-5: Components of the database environment

Note: All interactions with the database must go through the DBMS

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Evolution of Database Systems

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Current Development

• Relational DBMS has > 80% market share

• Major Database Vendors– Oracle: Oracle 11g, Oracle 12c– IBM: DB2, Informix– Microsoft: MS SQL Server– SAP: Sybase– Teradata: Teradata

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Current Development• Overall Market Share in 2012

– Oracle, IBM, and Microsoft dominate the market

Source: Gartner, March 2013

Oracle, 48.30%

IBM 19.30%

Microsoft 18.17%

Others 14.23%

RDBMS Market Share

OracleIBMMicrosoftOthers

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Current Development• Oracle

– strong customer base on enterprise RDBMS market– industry recognition of Oracle 11g and 12c– strong penetration in Linux/Unix platforms

• IBM– DB2 dominates mainframe platforms

• Microsoft– strong penetration in Windows platform– getting popular particularly with Small and Medium Enterprises

• Teradata– emphasis on business intelligence and data warehousing

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Review Questions

• Differences between data, database, information and metadata

• What are the disadvantages of file processing?• What is the database approach?• What are the advantages of the database approach?• What are the costs and risks of the database approach?• What are the range of database applications?• What are the components of the database environment?• What are the popular databases?

Database fundamentals(database)

Engineering

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