Report on Heterogeneous databases

The database system not being limited to a single system is basically the distributed database. There exist different sites on which this distributed system is spread. It may include multiple computers or the computers over a network. The sites where the distribute system is located does not make sharing for the physical components. It is required specifically in the case where it is required that the across the globe multiple users are to access the database. It is managed in the manner that the users perceive it to be the single database. A DBMS (database management system) can be classified to two main categories i.e., the homogeneous databases and the heterogeneous databases (quora, 2019) and (ecomputernotes, 2019).

Types of Distributed Database Management System

There are two types of distributed database environments such as homogeneous and heterogeneous. In this section, homogeneous database will be discussed.

Homogeneous Database

A homogeneous database is a type of distributed databasethat has the indistinguishable hardware as well as the software running all type of the instances of the databases, as well as it may appear by using a single user panel such as it were a single database.On the other side, it can have different kinds of operating systems, data models, and data structures, as well as different kinds of hardware for the distinguished database(Abouzeid, et al., 2009).

All sites have identical software in the homogeneous distributed database systemas well as all sites are aware of every other as well as agree for the cooperation in processes of the requests of the users. The part of its autonomy is surrounded by every site within the term of the right tochange the software of the database or the change in the schema.It is appeared by a homogeneous database management system for the user like a sing software or the system. The system of homogeneousis much easier for managing and designing.The following conditions mustbe satisfied for the database of homogeneous. The first one is the data structures used in every position that should be compatible or similar. The second one is the applications of the databases or the database management system (DBMS),which utilized at every position as well as it should also be compatible or similar(GUDAKESA, et al., 2014).

In simple words, in the homogeneous distributed database management system, the sites use asimilar or equal operating system as well as DBMS. There are some properties mentioned in this report such as every site focus to use same software, andit uses the same software, interface, hardware as well as the operating system from the similar type of the vendor. To process onthe requests of the users, every single site is also aware of all of the associated and non-associated sites as well as differentcooperate along with the other sites. Furthermore on the properties of the system, the database is also accessed by using the single user interface(Kumar & Sagnika, 2013).

Types of Homogeneous DDBMS

There are two types of the homogeneous distributed database system. The first type of homogeneous database is autonomous database, as well as the second type of homogeneous database, is non-autonomous database. Every database is self-governing that functions on its own. The controlling application integratesthose databases, as well as those databases,utilize the passing message for sharing updates of the data. In the non-autonomous database, the database distributes the data throughout homogeneous master DBMS or the central DBMS as well as the homogenous nodes or the coordinate’sdata updates throughout the sites(Kumar & Sagnika, 2013).

The homogeneously distributed database management system isillustrated in the figure below. There are four locations shown in the figure. Every single location has connected to the same database type name with Oracle, which is associated with the DBMS. Furthermore, every location that is shown in this figure can also be local or global. For instance, the user of the system of particular website can access the website from the local area of the country of the city or can use the website service from the other region of the world. In very simple words, the locations show the user interfaces within the figure as well as it also shows that the user can take the services from the local areas or from any other global areas of the world. Each computer, user panel, device or operating system have the same kind of the information the database technology, hardware as well as the software. For example, if the homogenously distributed database management system is developed and using the oracle databases, the whole locations must have to be implemented in the Oracle databases. All of the systems are connected with the same distributed database management system because it will help the user or the computer with the communication network(Aguilar, 2005).

Advantages or Disadvantages

There are several kinds of advantages and disadvantages of the distributed database management system. In the very simple and non-formal language, some advantages can be listed here. The advantages of homogeneous distributed database system are: it is very simple and easy to design, develop as well as use, easy to operate, handle and mange, as well as the design for the implementation such database is very simple and easy to understand for the developers of the database. On the other side, the disadvantage of the homogeneous database is: it is difficult or complicated for most of the organizations to force the environment of homogeneous distributed database system(Bilgaiyan & Sagnika, 2013).

Moreover, on the advantages of the homogenously distributed database system, it can increase the availability, and it is more reliable, expandable easily, replicates the structure of the organization such as it stores potentially the database fragments into the related departments. The local autonomy such as the data can be controlled by a particular department as well as the informative data into the database can also be handled by the department (Wada, et al., 2010).

Heterogeneous databases

The concept of heterogeneous databases deals with the concept of multiplicity. It can be said that it is the case where the individual database is implemented by the individual sites and their integration takes place at the large scale i.e., the centralized database servers are available. For the heterogeneous systems, different DBMSs tend to communicate with each other by having the translation resources (Garg, 2015). At the local site, the transparency to DBMS is brought by hitting the requests in the specified language. This language can better be interpreted by the DBMS. The data is then located by the system along with the desired translation work. The data may be required from the other sites. These sites may include as given:

·         Different hardware;

·         Various products of DBMS;

·         Different hardware along with various products of DBMS;

The process of translation is simple and straight forward in case there exists the similarity for the DBMS products but the difference exists for the hardware. Some of the translations may include the alteration to the codes along with the possible changes to the length of the words. The translation is more complex as well as complicated in case there exists the difference in the DBMS products. The complexity exists due to the complicated translations i.e., the data structure present in one model are mapped to the corresponding data structures in some other model (Yubiao Wang, 2016).

As an example we can say that the for the network model the records as well as the sets are provided by the relational data model. It is better done by making use of the relations of the relational data model. Also, it is mandatory to make translations for the query language. For example, it can be done by making mappings of the SQL select statements to the GET and Find statements of the available network. The above said two types of the translations are required if it is the case of the difference to both the software and the hardware. It helps to bring the complexity to the processing process. For the heterogeneous DBMS, a few relational databases serve this purpose by making use of the gateways. The main agenda behind making use of the gateways is to translate the model & the language of different DBMS to the model & the language of the relational database system.

Properties of the heterogeneous database

For the heterogeneous systems, different operating systems exist for different sites. Also, the DBMS products as well as the data models are different for the said database model. The significant properties of the heterogeneous database include as given:

·         The concept of dissimilarity exists in the usage of the software & the schemes. It is the case of different sites.

·          A variety of DBMs may combine to make the system. These DBMSs may include the network model, the relational data base model, the hierarchical model as well as the object-oriented model.

·         As the phenomenon of dissimilarity exists for the schemes, it tends to make the process of query processing more complicated.

·         Due to the dissimilarity in the software, the processing of the transactions becomes more complicated.

·         There are the chances that a site may not be aware of the other existing sites. It tends to limit the co-operations of the user sites in order to process the user’s requests.

Types of heterogeneous distributed databases

The important types of the heterogeneous distributed databases are as given:

·         Federated: These heterogeneous systems are independent in the performance of their functions. They show more integration with each other’s components. It helps these databases to serve as a single database system.

·         Un-federated: In order to access the databases through un-federated heterogeneous distributed databases, there exists a central module for the purposes of the coordination.

Architecture of heterogeneous distributed databases

The architecture of the heterogeneous distributed databases is given the figure below:

·         In the heterogeneous system, the DBEs tend to show the varying nature. For the world outside, there is a possibility to provide different interfaces through these DBEs. By doing so the differences of the DBEs is better hidden.

·         For the said purpose, the wrappers are used which help to hide the DBEs.

·         The wrappers are used in order to provide different functionalities for the heterogeneous distributed databases.

·         These wrappers are used as per the nature of the database model.

·         They also serve the purpose to cache the data as well as the information outside the database. It helps in the provision of the efficient services (Ques, 2019) and (oracle, 2019).

Figure: Architecture of Heterogeneous Database

References of Heterogeneous databases

Abouzeid, A., Bajda-Pawlikowski, K., Abadi, D. & Rasin, A. S. &. A., 2009. HadoopDB: an architectural hybrid of MapReduce and DBMS technologies for analytical workloads. Proceedings of the VLDB Endowment, 2(1), pp. 922-933.

Aguilar, A. C. M. &. J. L., 2005. Architecture for an intelligent distributed database. In 13th Euromicro Conference on Parallel, Distributed and Network-Based Processing , pp. 322-328.

Bilgaiyan, S. & Sagnika, N. K. &. S., 2013. An Overview of Transparency in Homogeneous Distributed Database System.. International Journal of Advanced Research in Computer Engineering & Technology (IJARCET), 2(10).

ecomputernotes, 2019. What is the difference between homogeneous and heterogeneous DBMSs. [Online]
Available at: http://ecomputernotes.com/database-system/adv-database/homogeneous-and-heterogeneous-distributed-dbmss

Garg, B., 2015. Integration of heterogeneous databases. Science Direct.

GUDAKESA, R., Sukarsa, I. & MADE, A. S. &. I. G., 2014. TWO-WAYS DATABASE SYNCHRONIZATION IN HOMOGENEOUS DBMS USING AUDIT LOG APPROACH. Journal of Theoretical & Applied Information Technology, 65(3).

Kumar, N. & Sagnika, S. B. &. S., 2013. An Overview of Transparency in Homogeneous Distributed Database System. International Journal of Advanced Research in Computer Engineering & Technology (IJARCET), 2(10).

Kumar, N. & Sagnika, S. B. &. S., 2013. An Overview of Transparency in Homogeneous Distributed Database System. International Journal of Advanced Research in Computer Engineering & Technology (IJARCET), 2(10).

oracle, 2019. Distributed database architecture. [Online]
Available at: https://docs.oracle.com/html/E25494_01/ds_concepts001.htm

Ques, 2019. What are the Homogeneous and Heterogeneous Distributed DBMS. [Online]
Available at: https://www.ques10.com/p/17615/what-are-the-homogeneous-and-heterogeneous-distr-1/

quora, 2019. What are homogeneous & hetrogeneous distributed DBMS?. [Online]
Available at: https://www.quora.com/What-are-homogeneous-hetrogeneous-distributed-DBMS

Wada, Y., Watanabe, Y., Syoubu, K. & Katoh, J. S. &. T., 2010. Virtual database technology for distributed database. In 2010 IEEE 24th International Conference on Advanced Information Networking and Applications Workshops, pp. 214-219.

Yubiao Wang, J. W., 2016. Research on Incremental Heterogeneous Database Synchronization Update Based on Web Service. IEEE, pp. 1-15.