Comparing Assignment 3 Databases: Bristol Energy Network (Coursework Sample)

nergy system
Energy is an important aspect of all our lives.
We use energy, such as electricity and gas, to
heat our homes and buildings, heat water, cook
our food and much more. However, our current
energy system is not working for everyone.
Bristol Energy Network is an umbrella
organisation for individuals and community
groups with an interest in energy in Bristol and
the surrounding area. BEN has over twenty
member groups working towards a fair,
sustainable energy system. They are involved in
many different energy projects, including
assisting people struggling to pay their energy
bills, advising people on how to reduce their
energy use and raising money for and installing
community-owned renewable energy projects (eg
installing solar panels on community buildingsNAME:
SUBJECT:
LECTURER:
COURSE NUMBER:
DATE:
COMPARING THE THREE MAIN DATABASES
A database is a shared logic combination of similar data i.e. analysis of the data meant to meet the general needs of a specific institution or organization. In another case, it can be defined as a combination of data that can be used comfortably by multiple users at the same time. The three databases commonly used in the modern world are namely; relational, hierarchical and Network
Databases have adapted to dynamic changes in time and needs as the information management requirements of individual and organizations have advanced becoming more complex and overloaded with a lot of information from their specified clients or members. Ranging all the way from traditional files to relational databases, the trending demands on accurate data, reliability, integrity and execution of database management systems (DBMS), has rationalized the design, current reformation and upcoming of databases and their underlying models (John, “Porter Research Associate” 77).
In reference to this essay document, three categories of database models have been critically discussed evaluating and investigating their major functionalities in regard to their specified applications in the specified companies and organizations. The three databases in order of their discussion are Hierarchical, Network and Relational.
Hierarchical Database Model
It is the oldest of the three databases in the above discussion. Basing on its origin, it is an advanced modification of the flat-file database system since it comprises of a simple data relationship scheme in its basic outline. The outlook in regard to hierarchical database model is child/parent relationships. The word “hierarchical” is derived from one common restriction on the child/parent interactions, it is embraced simultaneously, although a parent identity can hold several child entities, a child entity can only have one parent that is either the father or the mother.
For this reason, all the database interacts forming a hierarchy traced back on one root. Moreover, this model is often observed as an upside-down tree, where the entity at the top is viewed as a root and as such all other entities originate from the root (Connolly & Beg, “Database systems” 4th.E. d)
The major challenge with this type of model is the increased risk of data variation in terms of trends and formatting styles. We consider using customer to demonstrate this case since a separate “buyer” table must exist for each commodity line due to the fact that a child entity cannot have more than one parent. However, there is a higher probability that there are many customers or buyers who purchased more than one type of product (Connolly & Beg, “Database systems” 4th.E. d). Definitely, information about those product users must exist in more than one table leading data redundancy.
Another issue of focus with this model is its inflexibility. For example, if the database is limited to four commodity lines. Adding a new item line into the system would require predesigning the database simply because all the relationships must be defined once more. Finally, another issue of concern with the hierarchical model is in the child/parent interaction restriction. Every child is objected to have a single parent. Therefore, in the example above, it is difficult to add new buyers who have not purchased any new commodity yet. To overcome some of the limitations in hierarchical model, the network model must be predefined.
Network Database Model
This database management system uses a data model similar to Hierarchical database management systems. In general, the difference is that the tree structure in the Network models can have more parent to several children relational model. Its basic structure is based on records/sets and most of these databases use SQL for execution of their data. Network database management systems tend to be very flexible in spite of being used rarely. They were very commonly used in the1950s and 1960s (Hernandez, “what is database” 17). Fetching an item in this database system requires the code to traverse the entire data set which is quite difficult.
Furthermore, this database system is an improvement to its mother, the hierarchical model. In the network system, a child entity can have a chance of having more than one parent. This means that, the data outline can be assumed as several inverted trees linked up by branches as opposed to the individual inverted tree characteristic of the hierarchical model. As discussed above the network database model eliminates the need to hold several “buyers” tables (Hernandez, “what is database” 17).
Data in this type of model can be fetched from an entity as opposed to the hierarchical model which requires access from the root entity. The relationships between entities happen through unique set data structures. Although the entities are not copied or duplicated, a unique set structure is required to enhance each of the one-to-many relationships. Similarly, to the hierarchical model, this system model is also navigational.
This poses a big challenge in complex designs since every user has to understand the database structure in order to use it. Moreover, with a predefined structure like in the hierarchical model, altering the structure of the database becomes a difficult job. The relational model eliminates many of these problems presented in the above discussed system model.
Relational Database Model
These database management systems are very effective in terms of data storage and execution. Today, they are widely used in many organization and companies to store various data and information. Moreover, they are believed to be relatively easy and quite efficient to use (Hernandez, “what is database” 17). The database systems are named so because of the characteristic of normalizing the data which is usually stored in lows and columns. The relational model relies on normalizing data within the set tables. The data in one table can be similar to the one in the same table or other tables which have to be correctly organized by merging one or more tables. This can be simply achieved by merging two or more tables to one, making an efficient data retrieval. Relational models generally less efficient to other models; however, this may not be a challenge in their processing power and memory found in upcoming computers. Data in this type of model is stored in fixed predefined patterns and is usually executed using Structured Query Language (SQL). These database management systems include Oracle, MS SQL Server, IBM DB2, SQLite and PostgreSQL.
The relational model is based on the mathematical set theory. In this model, “data is stored in packages which are perceived by the user as relations” (Hernandez, “what is database” 17). The relations are composed of tuples (rows) and attributes (columns). Each record is identified by a row with a unique value. The order of the rows and columns defines the data storage capacities. Therefore, these system management models are independent of physical implementation, a quality that makes them more preferable to the hierarchical and database models.
Relationships in this model can be one-to-one, one-to-many, or many-to- many. Regardless of the type of relationship, the model is visible to the user i.e., the user...