Transcript Database - Sirikorn

954245
Chapter 1
Introduction to Database
Management
Modern Management and Information Technology
Collage of Arts, Media and Technology
Chiang Mai University
Outline
1. The Need for Databases
2. Hierarchy of Data
3. Types of Enterprise Data Storage
4. Components of Database System
5. DBMS Architecture
What is a database ?
• Give examples of databases
What is a database management
system?
• Give examples of databases management system
1. The Need for Databases
• Database Applications:
• Banking: transactions
• Airlines: reservations, schedules
• Universities: registration, grades
• Sales: customers, products, purchases
• Online retailers: order tracking, customized recommendations
• Manufacturing: production, inventory, orders, supply chain
• Human resources: employee records, salaries, tax deductions
• Databases can be very large.
• Databases touch all aspects of our lives
University Database Example
•Application program examples
• Add new students, instructors, and courses
• Register students for courses, and generate class
rosters
• Assign grades to students, compute grade point
averages (GPA) and generate transcripts
History of Database Management
Paper-based
• Paper
• Box card index
• Filling
File-based System
(Computerized)
• Magnetic tap file,
Magnetic disk, Hard disk
• Server
History of Database Systems
1950s and early 1960s:
• Data processing using
magnetic tapes for storage
• Tapes provided only
sequential access
• Punched cards for input
Late 1960s and 1970s:
• Hard disks allowed direct access to
data
• Network and hierarchical data
models in widespread use
• Ted Codd defines the relational
data model
• Would win the ACM Turing Award for
this work
• IBM Research begins System R
prototype
• UC Berkeley begins Ingres prototype
History of Database Systems
1980s:
• Research relational prototypes
evolve into commercial systems
• SQL becomes industrial standard
• Parallel and distributed database
systems
• Object-oriented database systems
1990s:
• Large decision support and datamining applications
• Large multi-terabyte data
Early 2000s:
• XML and XQuery standards
• Automated database
administration
Later 2000s: NoSQL and NewSQL
• Giant data storage systems
• Google BigTable, Yahoo PNuts,
Amazon, ..
2. Hierarchy of
Data
https://en.wikipedia.org/wiki/Data_hierarchy
Database Concept
http://www-
Hierarchy of Data
• Bit (Character) - a bit is the smallest unit of data
representation (value of a bit may be a 0 or 1). Eight bits
make a byte which can represent a character or a special
symbol in a character code.
• Byte- a unit of digital information that most commonly
consists of eight bits to encode a single character, for
example: 01000001 which is binary number to represent A
• Field - a field consists of a grouping of characters. A data
field represents an attribute (a characteristic or quality) of
some entity (object, person, place, or event).
Hierarchy of Data
• Record - a record represents a collection of attributes
that describe a real-world entity. A record consists of
fields, with each field describing an attribute of the
entity.
• File - a group of related records. Files are frequently
classified by the application for which they are
primarily used (employee file). A primary key in a file is
the field (or fields) whose value identifies a record
among others in a data file.
Hierarchy of Data
• Database - is an integrated collection of logically
related records or files. A database consolidates
records previously stored in separate files into a
common pool of data records that provides data for
many applications. The data is managed by systems
software called database management systems
(DBMS). The data stored in a database is independent
of the application programs using it and of the types of
secondary storage devices on which it is stored.
3. Types of Enterprise Data Storage
• Computer data storage in earliest era
• Each department store their own data
File-based System
• Increasing of stored data causes data
redundancy
• A database contains an organized
collection of data which each of the data
is related to one another. This data is used
Database System to handle operational functions of the
organization and is kept systematically at
the central data storage. So, it can be
Question
1. Filebased
System
2. Database
System
Question
1. Filebased
System
2. Database
System
File-based System
• A file based system is a collection of application
programs that perform services for the users wishing
to access information. Each program within a file
based system defines and manages its own data.
Old File Processing Systems at
Pine Valley Furniture Company
Computer
System for Pine
Valley Furniture
Company
File-based System
Advantages
• Suitable for small system
• Simply
• Easy to design and
implement
• Less of data
Disadvantages
• Data separation/
isolation
• Data duplication/
redundancy
• Data dependence
• Data inconsistency
• Fixed queries
Database System
Advantage
Disadvantage
• Minimized data inconsistency
• Reduced data redundancy
• Sharing data
• Accurate and reliable data
• Use the same standard
• Security
• Greater independence of the
data and programs
• Have higher costs of
hardware, software, and
others
• Complexity from the
application programs and
users
• High risk and high impact of
system failure
4. Components of Database System
•Hardware
•Software
•Data
•People
•Procedure
Hardware
• Hardware refers to all of the system’s physical devices
• For example, computers (PCs, workstations, servers,
and supercomputers), storage devices, printers,
network devices (hubs, switches, routers, fiber
optics),and other devices (automated teller machines,
ID readers, and so on).
Software
•Operating system software
• Microsoft Windows, Linux, MacOS, UNIX, and MVS.
•DBMS software
• Microsoft’s SQL Server, Oracle Corporation’s
Oracle, Sun’s MySQL, and IBM’s DB2.
•Application programs and utility software
Data
• The most important component of the DBMS
• Databases are defined, constructed and then data is
stored, updated and retrieved to and from the
databases.
• The database contains both the actual (or operational)
data and the metadata (data about data or
description about data).
People/ Users
• System administrators
• Database designers
• System analysts
• Programmers
• End users
Procedures
• Procedures refer to the
instructions and rules that
help to design the database
and to use the DBMS.
• The users that operate and
manage the DBMS require
documented procedures on
hot use or run the database
management system. These
may include.
• Procedure to install the new
DBMS.
• To log on to the DBMS.
• To use the DBMS or
application program.
• To make backup copies of
database.
• To change the structure of
database.
Database Access Language
• Used to access the data to and from the database
• The most popular database access language is SQL
(Structured Query Language)
• Users use the database access language to enter new
data, change the existing data in database and to
retrieve required data from databases.
5. DBMS Architecture
• External Level
• Conceptual
Level
• Internal Level
User 1’s view
conceptual schema
internal schema
Database
User 2’s view
DBMS Architecture
• A database management system provides three views of
the database data:
• The external level defines how each group of end-users
sees the organization of data in the database. A single
database can have any number of views at the external
level.
• The conceptual level unifies the various external views into
a compatible global view.[31] It provides the synthesis of
all the external views. It is out of the scope of the various
database end-users, and is rather of interest to database
application developers and database administrators.
DBMS Architecture
• The internal level (or physical level) is the internal
organization of data inside a DBMS. It is concerned with
cost, performance, scalability and other operational
matters. It deals with storage layout of the data, using
storage structures such as indexes to enhance
performance. Occasionally it stores data of individual
views (materialized views), computed from generic data, if
performance justification exists for such redundancy. It
balances all the external views' performance
requirements, possibly conflicting, in an attempt to
optimize overall performance across all activities.
Database languages are special-purpose
languages, which do one or more of the
following:
• Data definition language (DDL)– defines data types
and the relationships among them
• Data manipulation language (DML)– performs tasks
such as inserting, updating, or deleting data
occurrences
• Query language – allows searching for information
and computing derived information
QUESTIONS?
Report
PowerPoint presentation: 25-30 slides
1.
2.
3.
4.
5.
6.
Big data and Hadoop
NoSQL
Internet of things
Cloud computing
Social media
Mobile application
References
• Hoffer, J.A., Ramesh, v., and Topi, H. (2013). Modern Database
Management. 11th ed. ISBN 978-0-13-266225-3
• http://www.computingstudents.com/notes/database_systems/inde
x.php
• http://www.myreadingroom.co.in/images/stories/docs/dbms/comp
onents%20of%20database%20system%20environment.pdf