Introduction to DBMS

by K. Yue

1. Resources

Elmarsi's student resource is no longer available: you may be able to download PPT slides of the textbook here (We will not just follow the textbook or its Powerpoint slides.)
Read Chapter 1 of Elmasri.

2. Introduction to DBMS

Data management is increasingly crucial:

Explosion of data volume due to rapid technology advances.
Supply drives demand.
Technology drives demand.
New technologies become technically and economically feasible: e.g. Google's data center (13 planned or built centers as of 1/2015), a study of data center sizes in 2014.
Technology options are more abundant.

How large is the data size of the world and how quick does it grows? (2013 answer below).

one estimate by EMC on the digital universe:
- 2013: 4.4 Zettabytes (10 ^ 21)
- 2020: 44 Zettabytes
- Double every two years
One estimate of storage capacity of Google's Data Center: 10 Exabytes
- 13 data centers: largest data center about 1 million square feet.
- 1 million servers
- Largest data center: SuperNap, 2.2 million square feet.

Forward to 2018, data size of the world is estimated to be 33ZB. Three of the top five largest data centers are in China, with the largest data center being China Telecom Data Centre, built in Inner Mongolia with 10.7 million square feet. SuperNap expanded to 3.5 million square feet to hold the #7 position.

Forward to 2020, data size of the world is estimated to be 59ZB.

What it means to CS/CIS/IT students:

A career in database.
Applications are more data-driven.
Database is ubiquitous.

Ultimately, a database system is used to store and retrieve persistent data. Two main questions:

How is data stored? data model and storage mechanism.
How is data retrieved? querying.

These two questions are tightly related to each other.

Example:

How are data stored and retrieved in MS Words and Excel?

Question:

When do you want to use a DBMS?

Some key functionality and advantages of DBMS:

Controlling redundancy
Higher level of data abstraction
Data consistency support
Scalability
Performance
Security control and user management
Backup and recovery
Persistence of data and structures
Development life cycle support
High level querying support
Tools
Standards
Communities

Classwork 1

Select one advantage of DBMS that you are mostly familiar with and one least familiar. Conduct an SEE exercise.

State: the main concept using your own words.
Elaborate: provide key supporting concepts to elaborate the main concept in your own words.
Exemplify: provide examples to explain the concepts in your own words.

Classwork 2

State some disadvantages of using DBMS.