1. BUDGE BUDGE INSTITUTE OFTECHNOLOGY
Affiliated to MAKAUT(formerly WBUT)& Approved by AICTE,NAAC
Accredited
Kolkata - 700 137, West Bengal, India
Phone : 033 2482 0676 / 0670
http://www.bbit.edu.in
Department of Computer Science and Engineering
NBA (National Board of Accreditation) valid from Academic Year2021-2022
TO 2023-2024 i.e. upto 30-06-2024.
CONTINUOUS ASSESMENT1(CA1)
AY-2022-2023(EVEN SEM)
(MAKAUT EXAMINATION)
Assessment Type- Presentation
1
University Roll Number: 27600120018
Name of the Student: LOVEKUSH KUMAR
Course Code: PEC-IT601B
Course Name: Distributed Systems
Semester 6th
Year 3rd
Department Computer Science & Engineering
Topic of Presentation
Distributed Database Management SystemWith
Reference ToIt`s Architecture
2. INTRODUCTION
Distributed Database
2
Database :- Logical interrelated collection of shared data along
with description of data physically distributed over a computer
network
A distributed database is basically a database that
is not limited to one system, it is spread over different
sites, i.e, on multiple computers or over a network of
computers. A distributed database system is located on
various sites that donât share physical components.
What is Distributed database?
A distributed database (DDB) is a collection of multiplelogically
interrelated databases distributed over a computer network
A distributed database management system (DDBMS) is
the software that manages the DDB and provides an access
mechanism that makes this distribution transparent to the users
3. A Distributed Database Management System mainly
3
classified into two types
1.Homogeneous Distributed database management systems
2. Heterogeneous Distributed database management systems
4. Homogeneous DDBMS
In a homogeneous distributed database all sites have identical
software and are aware of each other and agree to cooperate in
processing user requests.
The homogeneous system in much easier to design and manage
The operating system used at each location must be same or
compatible
The database application (or DBMS) used at each location must be
same or compatible
Heterogeneous DDBMS
In heterogeneous distributed database different sites may use
different schema and software
In heterogeneous systems different nodes may have different
hardware & software and data structures at various nodes or
location are also incompatible
4
5. Characteristics
1. All sites are interconnected.
2. Fragments can be replicated.
3. Logically related shared data can be collected.
4. Data at each and every site is controlled by the DBMS.
5. Each Distributed Database Management System takes part in at
least one global application.
Functionality
1. Security
2. Keeping track of data
3. Replicated data management
4. System catalog management
5. Distributed transaction management
6. Distributed database recovery
Different computers and operating systems database application
or data models may be used at each of the location
5
6. Advantages
Less danger of a single-point failure. When one of the computers
fails the workload is picked up by other workstations.
Data are also distributed at multiple site.
The end user is able to access any available copy of the data and
an end user request is processed by any processor at the data
location
Disadvantages
Complexity of management and control.
Application must recognize data location and they must be able to
stitch together data from various sites
Security.
6
7. Architectural models of distributed databases
The systems sharing multiple DBMS are characterized withrespect
to Autonomy, distribution heterogeneity
Autonomy:- this refers to the distribution of control and not of data.
The dimensions of autonomy can be
- Design Autonomy
- Communication Autonomy
- Execution Autonomy
Distribution:- this refers to the distribution of data
- Client server
- Peer to peer
Heterogeneity:- this range from hardware heterogeneity networking
protocols data models query languages and transaction
management protocols
7
9. Distributed database architecture
1.Client server
2.Peer-to-peer
Types of client-server architecture
There are 2 types of client server architecture
1. Multi-client and single server
2. Multi-client and multi-server
Client manages its own connections to appropriate server. This
architecture simplifies the server code but loads client machines
with additional responsibilities.
This is heavy client
Client knows only of the home servers which then communication
with other servers as servers as required. Loads the server more
and is called as light client
9
10. Peer-to-peer database architecture
Global conceptual schema:- Given the enterprise view of data.
Union of all local conceptual schema
Fragmentation and Allocation schema:- task care of fragmentation
and allocation of data
Local conceptual schema:- Logical organization of data at each site
External schema:- user access and user applications
A peer-to-peer network is designed around the notion of equal peer
nodes simultaneously functioning as both "clients" and "servers" to
the other nodes on the network. This model of network arrangement
differs from the clientâserver model where communication is
usually to and from a central server
10
