This document discusses different types of databases including web-based databases, distributed databases, and data warehousing. It describes the components of a web-based database system including web browsers, web servers, application servers, and a DBMS. Distributed databases allow data to be accessed and modified across multiple computers using a network, while each local database is controlled by its own DBMS. Data warehousing involves integrating data from multiple sources to support analytics and decision making.

1. Different DATABASES
Tharindu Weerasinghe
www.tharinduweerasinghe.com

2. * The number of web-based enterprise software is
gradually getting popular. And those software use
Databases. Hence automatically the usage of web-based
DBMS is going up!
* Caters platform independence
* Provides Graphical User Interfaces (GUIs)
* Scalable
Web-based DB
Why?

3. Architecture of a Web Based Database
System

4. COMPONENTS:
* Web Browser – provides the connectivity to the internet
* Web Server - receives requests from a Web Client. The Web Server simply
retrieves the page defined by its URL and sends it to the Web Browser. Often,
the Web Browser has to execute a program in order to assemble a dynamic
page. In this case, the Web Browser has to access data in a DBMS
* Application Servers – they are optional but are recommended for the Web
architecture. They facilitate the execution of programs and include security,
session management and so on.
* Software application interfaces with the Application Server to provide the
pages.
* DBMS interfaces with the Application Server to provide the data needed. [1]

5. * A distributed database looks like a single database but it
is a set of databases stored on multiple computers.
* The data on several computers can be simultaneously
accessed and modified using a network.
* Each database server in the distributed database is
controlled by its local DBMS, and each cooperates to
maintain the consistency of the global database. [2]
Distributed DB

6. Architecture of a Distributed Database System
A schema object (for example, a table) is
accessible from all nodes that form a
distributed database.
Therefore, just as a non-distributed local
DBMS architecture must provide an
unambiguous naming scheme to distinctly
reference objects within the local database, a
distributed DBMS must use a naming scheme
that ensures that objects throughout the
distributed database can be uniquely
identified and referenced.

7. CREATE PUBLIC DATABASE LINK sales.division3.acme.com ... ;
SELECT * FROM scott.emp@sales.division3.acme.com;

8. Data Warehousing
Data warehousing is the process of constructing and using a data
warehouse.
A data warehouse is build by integrating data from multiple different
sources that support analytical reporting, structured and/or on
demand queries, and decision making.
Data warehousing involves data cleaning, data integration, and
data consolidations.

9. Data Warehousing –
Example
In the cooperate world, a data warehouse might incorporate
customer information from a company's point-of-sale systems
(the cash registers), its website, its mailing lists and its comment
cards.
And also, it might incorporate all the information about
employees, including time cards, demographic data, salary
information, etc

10. Gratitude
References:
[1] https://www.w3schools.in/dbms/web-based-database-management-system/
[2] https://docs.oracle.com/cd/A57673_01/DOC/server/doc/SCN73/ch21.htm
[3] https://www.tutorialspoint.com/dwh/dwh_data_warehousing.htm
[4] https://techburst.io/data-warehouse-architecture-an-overview-2b89287b6071
[5] https://investinganswers.com/financial-dictionary/businesses-corporations/data-warehousing-
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