The Evolution Of Database Management System

The Evolution Of Database Management SystemIn the ancient times when there was no computer, the selective in homunculusation began to be stored in voluminous entropy repositories, called books. And eventually with the improvement in technology and expansion in knowledge the whole communities of books transferred to the first real infobase libraries. The main objective of the entropybase is to ensure that data stinkpot be stored and retrieved easily and effectively. It is a compilation of data (records) in a structured way. In a database, the culture is stored in a tabular appoint where data may or may not be interlinked. Hence we base say that essentially database is a compilation of database registers and each database file is save a collection of records.Database beatsFlat files (1960s 1980s)Flat file database is a database that stores information in a single file or table. In a textbook file, every line contains one record where palm either have fixed length or they atomic number 18 separated by commas, whitespaces, tabs or both other character. In a flat file database, there is no structural relationship among the records and they cannot contain multiple tables as well.AdvantagesFlat file database is silk hat for small databases.It is hands-down to understand and implement. Fewer skills atomic number 18 inevitable to handle a flat file database.Less hardw ar and softw be skills are required to maintain a flat file database.DisadvantagesA flat file may contain fields which duplicate the data as there is no automation in flat files.If one record is to be deleted from the flat file database, then all the relevant information in different fields has to be deleted manually making the data manipulation inefficient.Flat file database waste the computer space by requiring it to keep the information on items that are logically cannot be available.Information retrieving is very time consuming in a large database.Implementation of a flat file data baseFlat file database is implemented inBerkeley DBSQLiteMimesisTheIntegrationEngineer etc.Hierarchical database (1970s 1990s)As the name indicates, hierarchical database contains data in a hierarchically-arranged data. More perceptively it can be visualized as a family tree where there is a call down and a child relationship. Each parent can have many children unless one child can only have one parent i.e. one-to-many relationship. Its hierarchical structure contains levels or segments which are equivalent to the file systems record type. each attributes of a specific record are listed under the entity type.In hierarchical database, the entity type is the main table, rows of a table re set up the records and columns represent the attributes.In the in a higher place figure, CUSTOMER is the parent and it has two children (CHCKACCT SAVEACCT).AdvantagesIn a hierarchical database pace of accessing the information is speedy due to the predefined paths. This increases the performanc e of a database.The relationships among different entities are easy to understand.DisadvantagesHierarchical database model lacks flexibility. If a new relationship is to be established between two entities then a new and possibly a unembellished database structure has to be build.Maintenance and of data is inefficient in a hierarchical model. Any change in the relationships may require manual shakeup of the data.This model is also inefficient for non-hierarchical accesses.Network database (1970s 1990s)The inventor of network model is Charles Bachmann. Unlike hierarchical database model, network database allows multiple parent and child relationships i.e., it maintains many-to-many relationship. Network database is basically a graph structure. The network database model was created to achieve three main objectivesTo represent complex data relationships more(prenominal) effectively.To improve the performance of the database.To implement a database standard.In a network database a r elationship is referred to as a isthmus. Each set comprises of two types of records, an owner record which is same as parent type in hierarchical and a member record which is similar to the child type record in hierarchical database model.AdvantagesThe network database model wees the data access quite easy and proficient as an application can access the owner record and all the member records within a set.This model is conceptually easy to design.This model ensures data integrity because no member can exist without an owner. So the user must make an owner entry and then the member records.The network model also ensures the data independence because the application works independently of the data.DisadvantagesThe model lacks structural independence which means that to beat any change in the database structure the application program must also be modified before accessing the data.A user friendly database oversight system cannot be established via network model.Implementation of network databaseNetwork database is implemented inDigital Equipment Corporation DBMS-10Digital Equipment Corporation DBMS-20RDM EmbeddedTurbo personaUnivac DMS-1100 etc.Relational database (1980s present)Relational database model was proposed by E.F. Codd. After the hierarchical and network model, the birth of this model was huge step ahead. It allows the entities to be related by means of a common attribute. So in order to relate two tables (entities), they simply need to have a common attribute. In the tables there are primary keys and alternative keys. Primary keys form a relation with the alternative keys. This property makes this model extremely flexible.Thus using relational database ample information can be stored using small tables. The accessing of data is also very efficient. The user only has to enter a query, and the application provides the user with the asked information.Relational databases are established using a computer language, Structured Query Language (SQL). This language forms the basis of all the database applications available today, from Access to Oracle.AdvantagesRelational database supports mathematical set of operations like union, intersection, difference and Cartesian product. It also supports select, project, relational join and division operations.Relational database uses normalization structure which helps to achieve data independence more easily.Security control can also be implemented more effectively by imposing an authorization control on the sensitive attributes present in a table.Relational database uses a language which is easy and human readable.DisadvantagesThe response to a query becomes time-consuming and inefficient if the number of tables between which the relationships are established increases.Implementation of Relational DatabaseOracleMicrosoftIBMMy SQLPostgreSQLSQLiteObject-oriented database (1990s present)Object oriented database management system is that database system in which the data or information i s presented in the form of objects, much like in object-oriented scheduling language. Furthermore, object oriented DBMS also facilitate the user by offering transaction support, language for heterogeneous queries, and indexing options. Also, these database systems have the ability to handle data efficiently over multiple servers.Unlike relational database, object-oriented database works in the framework of real programming languages like JAVA or C++.AdvantagesIf there are complex (many-to-many) relationships between the entities, the object-oriented database handles them much faster than any of the above discussed database models.Navigation through the data is much easier.Objects do not require assembly or disassembly hence saving the coding and execution time.DisadvantagesLower efficiency level when data or relationships are simple.Data can be accessible via specific language using a particular API which is not the case in relational databases.Object-relational database (1990s pr esent)Defined in simple terms, an object relational database management system displays a modified object-oriented user-display over the already implemented relational database management system. When motley software interact with this modified-database management system, they will customarily operate in a manner such that the data is assumed to be saved as objects.The basic working of this database management system is that it translates the useful data into organized tables, distributed in rows and columns, and from then onwards, it manages data the same way as done in a relational database system. Similarly, when the data is to be accessed by the user, it is again translated from processed to complex form.AdvantagesData remains encapsulated in object-relational database.Concept of inheritance and polymorphism can also be implemented in this database.DisadvantagesObject relational database is complex.Proponents of relational approach believe simplicity and purity of relational mo del are lost.It is pricey as well.Web enabled database (1990s present)Web enabled database simply put a database with a web-based interface.This implies that there can be a separation of concerns namely, the web designer doesnot need to know the details about the DBs underlying design. Similarly, the DB designer needs to concern himself with the DBs web interface.A web enabled database uses three layers to function a presentation layer, a middle layer and the database layer.AdvantagesA web-enabled database allows users to get the information they need from a central repository on demand.The database is easy and simple to use.The data accessibility is easy via web-enabled database.DisadvantagesMain disadvantage is that it can be hacked easily.Web enabled databases support the full range of DB operations, but in order to make them easy to use, they must be dumped down.