History of Relational Database
Hao-Wei He
Wilmington University
October 9, 2010
Abstract
Database system have been inseparable with our daily life, since IBM developed the hierarchical database management system in 1969, database system has been innovated many times, such as hierarchical database, network database, relational database, and object-oriented database. Nowadays, relational database still is the most popular model used by different industries; this article is going to introduce the history of the relational database.
History of Relational Database Data, which can be defined as an entity of meaning, it is the original material to construct message and knowledge. Thanks to the assistance of computer, data processing
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This concept also derived to the following data types:
* Hierarchical Data Model (1960s)
Use record as a processing unit, and organize record by tree structure. As a result of the characteristic of tree structure, hierarchical data model particularly suitable for describe “One to Many” data composition relationship but “Many to Many” relationship.
* Network Data Model (1970s)
As a result of the tree structure does not reflect network connection relationship between data and data, so after hierarchical data model, some groups proposed “Network Data Model”, organize records by network structure. However, records in both Hierarchical data model and network data model use link to strung together, so when programming applications must accommodate the structure status between links, a lot of dependencies between programming applications and data structure, and the independence of data is hard to reach, cause the system difficult to maintain.
* Relational Data
The data structure represents the logical relationships between data elements. In addition the data also determines the organizational structure, access methods, and alternative processing assosiativitas level for information.
Hierarchical database have data in a tree like structure with a parent to child relationship (one-to-many). The parent could have many children but the children have only one parent. All the attributes of the data is in a list under one entity type.
Data is defined as useful raw material which is intended to be useful for both the originator and for the intended receiver. Data consists largely of facts and figures ideal for communicating the intended meaning. This data can be interpreted and can be categorised as follows;
Data is the form of input, which can be produced into information. For example, 5000 could be the value of a piece of data that a business has. By adding context to this, for example if an organisation sold 1000 sandwiches in a week; this becomes information, which will influence important decisions
Data is facts and numbers that hasn’t been modified or analysed for example times and numbers. When data is by itself it has no meaning to it however information by itself does have a meaning.
An enterprise data model presents an abstraction of a more complicated real-world event or object. Generally, a data is graphical simple representation, of an interconnected real organization’s data structures. The main function of the data model is to help in understanding the complexities of a particular organization. A data model within a database environment brings out the data structures, their transformations, constraints, relations, and characteristics, thus providing a blueprint of
Data objects can model relational data or advanced data types such as graphics, movies, and audio. Smalltalk, C++, Java, and others are objects used in object-oriented data. The object-relational is a combination of relational and object-oriented databases. Traditional and advanced data types can be used to construct database management systems. These systems can connect to a company’s website and update records as needed. Database Approach The main purpose of a database is data storage that can be stored and retrieved when needed. A popular common language called structured query language (SQL) is used to store and retrieve data in relational database. This language enables the systems to run a report or modify data or remove the data from the database. A database management system (DBMS) controls all aspects of a database, this is not limited to the creation, maintenance, and use of database. The DBMS ensures proper applications are able to access the database. An important purpose of a DBMS is to maintain the data definitions (data dictionary) for all the data elements in the database. It also enforces data integrity and security measures. Data Models Data models provide a contextual framework and graphical representation that aid in the definition of data elements. In a relational database, the data model lays the foundation for the database and identifies important entities,
Data comprises of factual information. Data are the facts from which information is derived. Data is not necessarily informative on its own but needs to be structured, interpreted, analysed and contextualised. Once data undergoes this process, it transforms in to information. Information should be accessible and understood by the reader without needing to be interpreted or manipulated in any way.
Information: It is interpreted data which has been given meaning. It answers questions such as “who”, “what” and “where”. It is data which is organized and structured.
Data are raw facts that have no meaning until they are processed and organized to identify patterns and relationships between the data elements.
Relational database contains data records that do not have a preset of relationships, permitting the user to define his or her relationship when accessing the data. Since users have much control over the data being accessed, relational databases can perform a variety of tasks. Such as defining the database; querying the database; adding, editing, and deleting data from the database; modifying the structure of the database; securing data from public access; communicating within the network; and exporting and importing data (Murthy, 2008).
Data is information that is stored and organized by fields and records. A field which can also be known as an attribute is a single unit of information, like a surname of an IBM employee. A record or tuple is a collection of related fields. For example, an employee record contains all information fields that are relevant to a specific IBM employee. Additionally, a file (also known as a table) has multiple records that are pertaining to a specific topic. “To signify, an employee file of a hotel contains all employee records (Rob, 2010). Lastly, a database comprises all related files. A hotel database, among others, consists of employee files, room files, customer files, and payment files.”
Having and using a relational database prevents the duplication of data. Instead of saving lots of information within one table, you could divide up the table into information, for example in a college database you might have some tables with pupil names, age and addresses in a primary field like a pupil ID number. The field could then be related to another table which could be enrolment as a pupil “enrols” onto a “course” which would then be linked on another table called “teacher” which would decide the “room” they would be teaching in. When the table is made it has to be connected to other tables to be made into a database. Databases help to maintain precision, availability, usability, flexibility in an organisation
Data is ever increasing. We need a system to represent, store and manipulate complex information, detect correlations and patterns, construct data models etc. Furthermore, being independently maintained, data can change in time or even change its base structure, making it difficult for modelling systems to accommodate these changes. Current representation and storage systems are not very flexible in dealing with structural changes and also they are not powered with the ability of performing complex data manipulations of the sort mentioned above.
The conceptual schema for patient care as illustration of all of the data types required to manage the health-care process, whether using a relational, a hierarchical, or a combination of database structural designs, or an object-oriented structural database design. The structural design of a database required to be able to provide rapid retrieval of information for differnt patients and have the proficiency to adapt to changing information needs of growth and new technology; yet the primary purpose of the database structural design was to instrument the conceptual schema. It is necessary to first develop a model of the database that defined its functional requirements, its technical requirements, and its structural design to properly build a database. A formal description is expected of the database model, a conceptual schema of all the data generated in the enterprise, and how all of the data were linked. Thus the users of a medical database are expected to define its practical necessities as to exactly what the database and its database-management system to do. Since a medical database usually a part of larger medical-information system, the functional requirements of the medical database needed to be well-matched with those of the medical enterprise of which it was a part. Whether a medical database