1. Lecture 1 DBMS & More Atif Farid Mohammad Adjunct Professor UNCC

2. Introductions

3. How many of you know? PhP or ColdFusion or JavaScript

4. How many of you are? Grads or Undergrads

5. What are your majors? CS or SIS or Something Else

6. DBMS & More…
Textbook:
Fundamentals of Database Systems, Elmarsi/Navathe, Benjamin, 2011 (Sixth Edition)
Workload:
(30 %) 3 In Class Quiz
(30%) Midterm exam
(40% ) One project, parts 1 & 2

7. Any Questions ?

8. Objectives Introduction Example of database systems
Database characteristics
People associated with database
Advantage of Using a DBMS
Database implications
When Not to use a DBMS 8

9. Introduction Databases: Examples of Databases include:
Used to maintain information and to present data to users
Examples of Databases include:
Reservations systems (Hotel, Car, Airline)
Transactions processing systems (Online Banking systems, local library)
Investigations systems(Scientific Database systems)
Multimedia database systems
Geographic information systems (GIS) 9

10. Core Database Terminologies: 1
Any information (most likely in electronic form) worth preserving
E.g., names, addresses, grades, etc.
Database?
A collection of related data describing the activities of one or more organizations
Organized (or structured) for access and modification
Preserved over a long period
E.g. University Database 10

11. Core Terminologies: 3 Query?
an operation that extracts specified data from the database
E.g.
get the list of all courses and grades taken by “Smith”
Relation?
an organization of data into a two-dimensional table,
rows (tuples) represent basic entities or facts of some sort
columns (attributes or fields) represent properties of those entities.
Schema?
a description of the structure of the data in a database
also known as metadata 11

12. Database Def-1
A database is a shared collection of logically related data that is stored to meet the requirements of different users of an organization

13. A database is a self-describing collection of integrated records
Database Def-2
A database is a self-describing collection of integrated records

14. Database Def-3
A database models a particular real world system in the computer in the form of data

15. The concept of a shared organizational database
Management
Control
Planning
Marketing
Product
Development
Sales
Corporate
Database
Accounting
Accounts
Payable
Receivable
Manufacturing
Production
Scheduling

16. A bit of History
Computer initially used for computational/ engineering purposes
Commercial applications introduced File Processing System

17. File Processing System
A collection of programs that perform services for the end-users such as production of reports

18. File Processing Systems
Library
Applications
Data
Files
Examination
Applications
Data
Files
Registration
Applications
Data
Files
Program and Data Interdependence

19. File Processing Systems
Library
Exam
Registration
Reg_Number
Name
Father Name
Address
Books Issued
Class
Phone
Fine
Semester
Grade
Duplication of Data
Incompatible Formats
Vulnerable to Inconsistency

20. Database Approach

21. Advantages of Database Approach
Registration
Examination
Library
Applications
Database
Management
System
University
Students
Database
- Data Sharing
- Data Independence
- Controlled Redundancy
- Better Data Integrity

22. Data & Information Company: Super Soft Dept: Sales Emp Name Age Salary
Matt Damon 23 55
Bruce Willis 24
Katie Holmes 20 40
Robert Langdon 19

23. Schema
Database Applications
Database Management System (DBMS)

24. Other Advantages Data consistency Better data security
Faster development of new applications
Four minutes 24

25. They also provide Economy of scale Better concurrency control
Better backup and recovery procedures
5 mins, 9 tot 25

26. Disadvantages Higher costs Conversion cost More difficult recovery
Higher Costs include HW, SW, trained staff
Conversion Cost includes from Manual to DB or from File system to DB, both involve costs
4 mins, 13 tot 26

27. Typical Components Software Application Programs DBMS Data Database
End users
Software
interact
Application Programmers
Application Programs
develop
“What” to get
Database Administrators
DBMS
maintain
Database
“How” to get
Data
Database
Designers
design
Users

28. Levels of Data Real World Data Entity, Attribute
e.g. A student,
A class name
Record type, Data item type e.g. Student record type
Metadata
Explain from this and later text followed by this diagram
Data Occurrences
Student record, Data item occurrence e.g.
‘s001’, ’Amir’, ‘CS101’ 28

29. Employee name, age, qual, sal Emp Name text Age number Sal number
John Durso 23 55
Lisa Smith 24
Cindy Bates 20 40
Braden Sams 19

30. Levels of Data
Real-world data
Metadata
Data Occurrence
4/21 30

31. Database Users
Application Programmers
End Users
Naïve
Sophisticated

32. Roles in the Database Environment
Data Administrator (DA)
Database Administrator (DBA)
Database Designers (Logical and Physical)
Application Programmers
End Users (naive and sophisticated)

33. Functions of DBA Schema definition Granting data access
Routine Maintenance
Backups
Monitoring disk space
Monitoring jobs running

34. Database Properties A database must
Represent some aspects of real world
Collection of data must be logically coherent and meaningful
Database is designed, build, and populated with data for specific purpose 34

35. Database Construction
Database can be constructed
Manually
E.g., a library card catalog
Computerized system
A Specific set of applications
Database Mgt systems 35

36. Database Mgt system (DBMS)
Database management system (DBMS)?
A collection of programs that enables users
To define (specifying data type, etc)
To construct (storing)
To manipulate (reading, writing)
To share (simultaneous access)
To protect (security & privacy protection)
To modify (changing requirements)
Database system= DBMS + Database 36

37. 37

38. Example: University Database System
A typical university database system maintaining information regarding
Students
Courses
Grades 38

39. Example: A University Database39

40. Database Engineering Design of any DB application starts
Requirements definition and analysis
Conceptual Design
Performed using Entity relationship Diagram
Logical Design
Performed using Orcale / Mysquel, etc
Physical Design (storing/accessing/indexing) 40

41. Main Characteristics of DB
Self-Describing nature of a database system ( catalog =Data + metadata)
Insulation between programs and data ( program-data-independence)
Support of multiple views of the data (virtual data)
Sharing of data and multi-user transaction processing (concurrency control)
Transaction and atomicity
ACID 41

42. People involved in Database
Involved two types of people
people on the Scene
people behind the Scene 42

43. People on the Scene Database administrators (DBA) Database designers
Authorization, coordination, supervision of DB
Database designers
Defining, building, maintaining, etc
End Users
Casual, naive, sophisticated
Software Engineer
system analysts and application programmers 43

44. People behind the Scene
DBMS system designers and implementers
Tool developers
Operators and maintenance personnel 44

45. File System vs. Database Mgt Systems
Suppose an organization needs to manage a large collection of data, say, 500 GB (i.e., 500X1024 MB)
Data is supposed to be accessed concurrently by employees
Changes made to the data must be applied consistently
Access to the data must be restricted 45

46. File systems vs. A DBMS (cont’)
Using file systems, the data is stored in OS files
Not enough MM
Difficulty to directly access data (with 32-bit , we can access 4GB)
Need to write special program to answer each question
Duplicated efforts
inconsistency
Concurrent accesses
Security policies … 46

47. Primary Advantages of Using a DBMS: 1
Controlling Redundancy
Duplicate space and efforts
inconsistency
Restricting Unauthorized Access
Security and authorization subsystem
Providing persistent storage for program objects and data structure
Impedance mismatch problem (incompatibility between PL and DBMS)
Deriving new information from existing ones (view) 47

48. Primary Advantages of Using a DBMS: 2
Providing Multiple User Interfaces
Representing Complex Relationships among Data
Enforcing Integrity Constraints
Providing Backup and crash Recovery
Scheduling concurrent accesses to the data
Reducing application development time 48

49. Implication of the Database Approach
Standards can be enforced (data and display format)
Application development time can be reduced
Flexibility and maintainability
Availability of up-to date information
Economics of Scale (i.e., reducing overall costs of operations, sources and mgt) 49

50. When Not to Use A DBMS
When there is unnecessary overhead resulted from:
High initial up-front cost
Generality that a DBMS provides for defining and processing data
Overhead for providing
security
concurrency
recovery
integrity 50

51. When to Use File System
A File system is desirable under these conditions:
The database and application are simple, well-defined, and unchangeable
Single-user access to the data is required
performance 51

52. So, what is a Database? Collection of data central to some enterprise
Essential to operation of enterprise
Contains the only record of enterprise activity
An asset in its own right
Historical data can guide enterprise strategy
Of interest to other enterprises
State of database mirrors state of enterprise
Database is persistent

53. What is a Database Management System?
A Database Management System (DBMS) is a program that manages a database:
Supports a high-level access language (e.g. SQL).
Application describes database accesses using that language.
DBMS interprets statements of language to perform requested database access.

54. What is a Transaction?
When an event in the real world changes the state of the enterprise, a transaction is executed to cause the corresponding change in the database state
With an on-line database, the event causes the transaction to be executed in real time
A transaction is an application program with special properties - discussed later - to guarantee it maintains database correctness

55. What is a Transaction Processing System?
Transaction execution is controlled by a TP monitor
Creates the abstraction of a transaction, analogous to the way an operating system creates the abstraction of a process
TP monitor and DBMS together guarantee the special properties of transactions
A Transaction Processing System consists of TP monitor, databases, and transactions

56. Transaction Processing System
DBMS
database
transactions
DBMS
database
Transaction Processing Monitor

57. System Requirements
High Availability: on-line => must be operational while enterprise is functioning
High Reliability: correctly tracks state, does not lose data, controlled concurrency
High Throughput: many users => many transactions/sec
Low Response Time: on-line => users are waiting

58. System Requirements (con’t)
Long Lifetime: complex systems are not easily replaced
Must be designed so they can be easily extended as the needs of the enterprise change
Security: sensitive information must be carefully protected since system is accessible to many users
Authentication, authorization, encryption

59. Roles in Design, Implementation, and Maintenance of a TPS
System Analyst - specifies system using input from customer; provides complete description of functionality from customer’s and user’s point of view
Data Scientists: use all available data sources (internal and external) to analyze and gain insights to help decision makers.
Database Designer - specifies structure of data that will be stored in database.

60. Roles in Design, Implementation and Maintenance of a TPS (con’t)
Application Programmer - implements application programs (transactions) that access data and support enterprise rules
Database Administrator - maintains database once system is operational: space allocation, performance optimization, database security
System Administrator - maintains transaction processing system: monitors interconnection of HW and SW modules, deals with failures and congestion

61. OLTP vs. OLAP On-line Transaction Processing (OLTP)
Day-to-day handling of transactions that result from enterprise operation
Maintains correspondence between database state and enterprise state
On-line Analytic Processing (OLAP)
Analysis of information in a database for the purpose of making management decisions

62. OLAP Analyzes historical data (terabytes) using complex queries
Due to volume of data and complexity of queries, OLAP often uses a data warehouse
Data Warehouse - (offline) repository of historical data generated from OLTP or other sources
Data Mining - use of warehouse data to discover relationships that might influence enterprise strategy

63. Examples - Supermarket
OLTP
Event is 3 cans of soup and 1 box of crackers bought; update database to reflect that event
OLAP
Last winter in all stores in northeast, how many customers bought soup and crackers together?
Data Mining
Are there any interesting combinations of foods that customers frequently bought together?

64. Big Data Era
Every 2 days we create as much information as we did from the dawn of civilization up to (2010, Eric Shmidt, Google)
Science: Astronomy, Physics, Bioinformatics, Neuroinfomatics, earth science, etc.
Business: Automobile, Healthcare, Financial, infotaiment
The automotive industry is projected to be the 2nd largest generator of data by 2015

65. Big Data Opportunities to Auto
Google self-driving car (generates 1GB/s).
Recommendation/alert to customers.
Manufactures can better understand customers and market trends.
Better driving behaviors, better cars, less accidents, and the bottom line is happier customers.

66. Big Data Opportunities to Auto
Google self-driving car (generates 1GB/s).
Recommendation/alert to customers.
Manufactures can better understand customers and market trends.
Better driving behaviors, better cars, less accidents, and the bottom line is happier customers.

67. Why is Database Important in the Future?
“In the future, … any given discipline advances is likely to depend on… database, workflow management, visualization, and cloud computing technologies. “
G. Bell, T. Hey, A. Szalay, “Beyond the Data Deluge,” Science, Vol. 323, no. 5919, pp , 2009.

68. Turing Awardees in DB Charles Bachman (1973) Edgar F. Codd (1981)
Jim Gray (1998)

69. Charles Bachman
Developer of IDS: the first database system

70. Edgar. F. Codd
Inventor of the Relational Model

71. Jim Gray
Founder of Transaction Processing

72. Questions ?