Relational Database Management Systems
A relational database management system is a system which usually uses the standard method of cataloging, retrieving and running queries on data. It is used to manage the incoming data, organize it and provide ways for the data to be modified when need arises (Hull, 2009). The cycle is a series of seven stages and their procedure provides an understanding of problems and solutions which are likely to emerge during the design and implementation of a given database system. The stages followed in the life cycle and their support in the database design process is as follows:
Firstly, the designer of the database has to define a real life problem which will be solved by the creation of the database. The understanding of the problem should be as conclusive as possible in order to avoid errors and shoddy work. The understanding of a problem’s nature and constraints and outlining of the feasible outcomes is normally performed by the use of a system methodology analysis. This will enable designers to make up their mind up before embarking on the design process, this being the first stage of database design (Muttleder,2010).
Secondly, drawing of entity-relations is performed. This is usually in the form of diagrams which in their modified form acts essentially as a logical schema part. The logical schema is an attribute of the tables created in a given database. The attributes of various entities produced are then added to the diagrams. The specification of primary keys and foreign keys is performed at this stage.Checking of the entity-relational model is performed through the process of normalization. This process may result in the splitting and at times recombination of entities of various types. The table definitions and entity relations model which result from this normalization has to be consistent. The finalization of the required schema of table sets is performed. Thereafter, creation of database tables is actuated including the specification of foreign keys, database constraints and database integrity terms and condition specifications are also performed at this stage.
Stage six involves organization of files. This is how storage of database relations is performed on the storage medium. Database organization is on the basis of maximum access speed, type of the required access space of storage considerations.
At the seventh stage, queries are designed. A good idea is required by the designer about the main types of the queries and the reports which the database can accommodate. At the eighth stage, designing of application screens is worked upon. These screens are used in the capturing of input information to be stored in the database. Data items which have to be input and output of particular applications and human computer interface parameters determine the particular screen designing. Screen design is vital in data collection and storage in the database (Hull, 2009).
Report designing is the ninth stage. Specifications about what should be in the report, the report format and when the report should be produced are addressed at the aforementioned stage. This is meant to ensure deadlines are adhered to because punctuality is considered to be paramount. The tenth stage involves testing of application screens and data validations. It serves as the epitome test of correctness of database schema and system viability as a whole.
The final stage involves the handing-over. The finalized database and its applications are received by users. The users perform data entry. The system is implemented after handing the core system of the database. The purpose of relational database management system life cycle is important in ensuring that the database serves its sole purpose for which it was created for. For example, a database can be created to assist in the management of sales of a particular business enterprise. The inclusion of constraint makes sure that the operation of that particular database is within limits and serving the purpose.