1. Database Management Dr. Yan Quan Liu ILS, SCSU
Unit 10
Database Management Dr. Yan Quan Liu ILS, SCSU
KNOW THE DIFFERENCES BETWEEN THE FOUR TYPES OF DATABASES AND BE ABLE TO GIVE EXAMPLES

2. A system for organizing information
Database Management System (DBMS)
Design of Integrated Library Systems
Guide to library automated systems, library software, hardware configurations may be found at:
What is MARC?
What is Z39.50 Protocol and why is it important?
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ILS 501 / Dr. Liu, SCSU

3. Representation
It allows us to reach conclusions about the thing being represented by looking only at the representing world.
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ILS 501 / Dr. Liu, SCSU

4. Representation as mappings
A representation is something that stands for something else.
it is a kind of a model of the thing it represents.
distinguishing between a representing world and a represented world.
The representing world must mirror some aspects of the represented world.
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ILS 501 / Dr. Liu, SCSU

5. Representational system
What the represented world is,
What aspects of the represented world are being modeled,
What aspects of the representing world are doing the modeling,
What the correspondences are between the two worlds.
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ILS 501 / Dr. Liu, SCSU

6. Representational system
Metadata scheme
Classification
Subject heading
Index
Bibliography ……
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ILS 501 / Dr. Liu, SCSU

7. Data vs. information: What is the difference?
What is information?
Information is data that have been organized and communicated in a coherent and meaningful manner.
Data is converted into information, and information is converted into knowledge.
Knowledge; information evaluated and organized so that it can be used purposefully.
What is data?
Data can be defined in many ways. Information science defines data as unprocessed information.
9/19/2018
ILS 501 / Dr. Liu, SCSU

8. What is database? An organized collection of integrated files.
A shared collection of logically related data, designed to meet the information needs of an organization.
A collection of information organized in a way that a computer program can quickly select desired pieces of data.
Examples ?
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ILS 501 / Dr. Liu, SCSU

9. What is a database
A database is any organized collection of data. Some examples of databases you may encounter in your daily life are:
a telephone book
T.V. Guide
airline reservation system
motor vehicle registration records
papers in your filing cabinet
files on your computer hard drive. 
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ILS 501 / Dr. Liu, SCSU

10. Why do we need a database?
Keep records of our:
Clients
Staff
Volunteers
To keep a record of activities and interventions;
Keep sales records;
Develop reports;
Perform research
Longitudinal tracking
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ILS 501 / Dr. Liu, SCSU

11. What is the ultimate purpose of a database management system?
Is to transform
Data
Information
Knowledge
Action
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ILS 501 / Dr. Liu, SCSU

12. How is data structured when it is stored?
Data storage hierarchy
consists of the levels of data stored in a computer.
bits, bytes, fields, records, files & databases
Bits and bytes are the building blocks for representing data, whether it is being processed, stored, or telecommunicated.
Bit – the one or the zero
Byte – is the number or letter represented by the one or zero
Fields – a place to input data usually in bytes
Records – several fields
Files –
Databases –
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ILS 501 / Dr. Liu, SCSU

13. What is field?
Field - a unit of data consisting of one or more characters. It usually contains a fact about a person, place, thing or event.
A Key Field contains unique information so that it can be easily recognized and processed, and not be confused with another record.
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ILS 501 / Dr. Liu, SCSU

14. What is record? Record - a collection of related fields.
e.g. name, address and social security number
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ILS 501 / Dr. Liu, SCSU

15. What is file? File - a collection of related records.
e.g. Employees in the same department of a company
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ILS 501 / Dr. Liu, SCSU

16. Database Management System
DBMS is a software system that enables users to define, create, and maintain the database and provides controlled access to this database.
As a software manager, the software controls the structure of a database and access to the data
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ILS 501 / Dr. Liu, SCSU

17. Database Management System
A DBMS is a data storage and retrieval system which permits data to be stored non-redundantly while making it appear to the user as if the data is well-integrated.
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ILS 501 / Dr. Liu, SCSU

18. Database Management System
DBMS
Database
containing
centralized
shared data
Application #1 #2 #3
DBMS manages data resources like an operating system manages hardware resources
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ILS 501 / Dr. Liu, SCSU

19. Advantages of Database Approach
Program-Data Independence
Metadata stored in DBMS, so applications don’t need to worry about data formats
Data queries/updates managed by DBMS so programs don’t need to process data access routines
Results in: increased application development and maintenance productivity
Minimal Data Redundancy
Leads to increased data integrity/consistency
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ILS 501 / Dr. Liu, SCSU

20. Advantages of Database Approach
Improved Data Sharing
Different users get different views of the data
Enforcement of Standards
All data access is done in the same way
Improved Data Quality
Constraints, data validation rules
Better Data Accessibility/ Responsiveness
Use of standard data query language (SQL)
Security, Backup/Recovery, Concurrency
Disaster recovery is easier
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ILS 501 / Dr. Liu, SCSU

21. What does DBMS do?
Enables you to store, modify, and extract information from a database.
It can
reduce data redundancy
improve data integrity
increase user productivity
increase security
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ILS 501 / Dr. Liu, SCSU

22. Four common databases Hierarchical database Network database
Relational database
Object-oriented database
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ILS 501 / Dr. Liu, SCSU

23. Four common databases- Hierarchical database
A hierarchic data structure consists of a family or ordered set of trees. Data records in this system have a child-parent relationship - a child record has exactly one parent.
It is not flexible for adding new fields.
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ILS 501 / Dr. Liu, SCSU

24. Example of cruise ship reservation system
Hierarchical database - fields or records are arranged in related groups, resembling a family tree, with child (lower-level) records subordinate to parent (higher-level) records
The hierarchical database is the oldest and simplest of the four models.
It is quite rigid because the structure must be defined in advance.
The figure illustrates hierarchical database with an example of a cruise ship reservation system.
Example of cruise ship reservation system
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ILS 501 / Dr. Liu, SCSU

25. Four common databases- Network database
A network data structure can be regarded as an extended form of the hierarchic data structure, a child record can have any number of parents.
It maps out relationships between member records and owner records, such as scheduling system.
9/19/2018
ILS 501 / Dr. Liu, SCSU

26. Example of college class-scheduling system
Network database - similar to a hierarchical database, but each child record can have more than one parent record
Child record is called a member and may be reached through more than one parent, which is called an owner.
Network database is more flexible than the hierarchical arrangement.
It still requires that the structure be defined in advance.
There are limits to the number of possible links among records.
Example of college class-scheduling system
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ILS 501 / Dr. Liu, SCSU

27. Four common databases- Relational database
The relational model is the most popular and flexible data model. Data in it can be stored/accessed through a key field, a common piece of data.
It is often used for metadata storage and synchronization control, such as the motor vehicles database-storing account & transaction information
Another example: a thesaurus
9/19/2018
ILS 501 / Dr. Liu, SCSU

28. Example of state department of motor vehicles database
Relational database - relates (connects) data in different files through the use of a key field, or common data element
Data elements are stored in different tables made up of rows and columns.
The tables are called relations (files), the rows are called tuples (records), and the columns are called attributes (fields).
FACTOID: SQL (Structured Query Language) - the standard language used to create, modify, maintain, and query relational databases. SQL is pronounced as “sequel.” How did this acronym get such an unlikely pronunciation? The first structured query language was developed by IBM in the 1970s; its product name was “Sequel2.”
FACTOID: QBE (Query by example) - feature of most query languages in which the user asks for information in a database by using a sample record to define the qualifications he or she wants for selected records.
FACTOID: E. F. Codd is considered the “father” of relational database management systems—the most common model of databases. His article entitled “A Relational Model of Data for Large Shared Data Banks” was published in the June 1970 “Communications of the ACM.”
Example of state department of motor vehicles database
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ILS 501 / Dr. Liu, SCSU

29. Four common databases- Object-oriented database
It uses objects as elements within database files. Any type of data can be handled including not only simple data but also image, graphics, and audio/video data.
A practical application of this types of database is a Map collection.
Example: Facebook, YouTube, MySpace, LibraryThing
A relational database uses a key field, object-oriented can find based on images or words
9/19/2018
ILS 501 / Dr. Liu, SCSU

30. Bibliographic Databases
CONSULS
MadCat
iConn is also an example.
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ILS 501 / Dr. Liu, SCSU

31. Questions?
Thank You
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ILS 501 / Dr. Liu, SCSU