Advantages of DDBMS over centralised DBMS


Some of the advantages of DDBMS over centralized DBMS are:
  1. Reflects organizational structure
  2. Improved share ability and local autonomy
  3. Improved availability
  4. Improved reliability
  5. Improved performance
  6. Economics
1. Reflects organizational structure: We can distribute the data base over any organization offices which has distributed locations

For example:
A bank has many branches in different areas. It is needed to be distributing database over these locations. A bank may keep a database at each local branch office containing details such as the staff, the account information of customers etc.
The staff at a branch office will make local inquiries of the database stored. The staff at company headquarters will make global inquiries of the database stored at all or a number of branches.

2. Improved share ability and local autonomy: Users can use the data on a site which is stored at other sites. By this way the user can do local control of the data stored at other site too.
A global DBA is responsible for the entire system. For local level DBMS, the local DBA is allotted the responsibility to manage it.

For example:
We can use google or facebook authentication to use truecaller application  in our mobile phone.

Another example is, when we search something on net, like a dress or shoes etc. Than we get the same category of advertisements on any websites. How other website came to know what we were surfing. This is possible just because of DDBMS.
3. Improved availability: In DDBMS failure of system at a node will not stop it. On failure DDBMS will get rerouted, means it will work through another node or path. And will available always from different routes. In DDBMS some sites may get inaccessible due to failure but this means not that entire system is not accessible. But this advantage of DDBMS is not possible in centralized DBMS. In centralized DBMS on failure of a component enrite system will get stopped.
4. Improved reliability: The replication system make the data copy exist in many sites. So this insures the possibility of accessing to this data if there is any failure happened.

For example:
In a banking system, if data at local branch gets destroyed than still it will be accessible from any location, from its another copy available at headquarter.
5. Improved performance: The accessing speed of the data base can be improved, if we use remote centralized database. This removes the conflicts of using same database which were occurs in centralized DBMS.

For example:
In a banking system, data stored at headquarters is accessible to the many location or branches at a same time.
6. Economics: For making the organization systems more cost-effective to obtain separate computers, DDBMS allows us to create systems of smaller computer, its collective power equal the power of one large computer.

For example:
Computer system in a banking system.
7. Modular growth: This refers to the flexibility of DDBMS, where we can add a new site without any effects on the operations of other sites.

DISTRIBUTED SYSTEM covered following topics in these notes.

Python Programming ↓ 👆
Java Programming ↓ 👆
JAVA covered following topics in these notes.
JAVA Programs
Principles of Programming Languages ↓ 👆
Principles of Programming Languages covered following topics in these notes.

Previous years solved papers:
A list of Video lectures References:
  1. Sebesta,”Concept of programming Language”, Pearson Edu 
  2. Louden, “Programming Languages: Principles & Practices” , Cengage Learning 
  3. Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill. 
  4. E Horowitz, "Programming Languages", 2nd Edition, Addison Wesley

    Computer Organization and Architecture ↓ 👆

    Computer Organization and Architecture covered following topics in these notes.

    1. Structure of desktop computers
    2. Logic gates
    3. Register organization
    4. Bus structure
    5. Addressing modes
    6. Register transfer language
    7. Direct mapping numericals
    8. Register in Assembly Language Programming
    9. Arrays in Assembly Language Programming


    1. William stalling ,“Computer Architecture and Organization” PHI
    2. Morris Mano , “Computer System Organization ”PHI

    Computer Network ↓ 👆
    Computer Network covered following topics in these notes.
    1. Data Link Layer
    2. Framing
    3. Byte count framing method
    4. Flag bytes with byte stuffing framing method
    5. Flag bits with bit stuffing framing method
    6. Physical layer coding violations framing method
    7. Error control in data link layer
    8. Stop and Wait scheme
    9. Sliding Window Protocol
    10. One bit sliding window protocol
    11. A protocol Using Go-Back-N
    12. Selective repeat protocol
    13. Application layer
    1. Andrew S. Tanenbaum, David J. Wetherall, “Computer Networks” Pearson Education.
    2. Douglas E Comer, “Internetworking with TCP/IP Principles, Protocols, And Architecture",Pearson Education
    3. KavehPahlavan, Prashant Krishnamurthy, “Networking Fundamentals”, Wiley Publication.
    4. Ying-Dar Lin, Ren-Hung Hwang, Fred Baker, “Computer Networks: An Open Source Approach”, McGraw Hill.