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E.f codd rules for RDBMS which makes any database as Relational Database
E.f codd rules for RDBMS which makes any database as Relational Database
E.F. for RDBMS Codd had created 12 rules that, if followed by a database management system, that DBMS can be called Relational Databases Management System.
Rule 0: Foundation rule - Every Relational database
Rule 1: Rule of Information - All the information available in the relational database should be kept in the same form as a table.
Rule 2: Rule of Guaranteed Access - It should be ensured that every data in the database is accessed based on table name, primary key and column name etc.
Rule 3: Rule of Systematic Null Value Support - While we insert insertion of records in the database, many values are omitted by us, which should be treated as null values in the relational database, null value is neither Blank Space. And there is no zero.
Rule 4: Rule of Comprehensive Data Sub-language - It is necessary to have at least one language support through each database, usually SQL - Structure Query Language is used in all RDBMS.
Rule 5: Rule of Active and online relational Catalog - In the same way as the data is accessed in a relational database, the database structure should also have access to it.
Rule 6: Rule of Updating Views - In a relational database, the methods of logical representation of a table are called View. Each View should support a similar Full Range of data manipulation.
Rule 7: Rule of Set level insertion, update and deletion - Insert updates and delete functions in relational databases should be done in a single statement.
Rule 8: Rule of Physical Data Independence - The physical method to obtain and store information from the database must be separate from the user.
Rule 9: Rule of Logical Data Independence - The logical structure of the database or changes made in the table, which should not be read on the data viewing method.
Rule 10: Rule of Integrity Independence - The database must have the necessary constraints in the database to maintain the integrity of the data being input by the user. OR In this rule any component of Primary key can not contain NULL values
Rule 11: Rule of Distribution Independence - When working in a relational database, the user should be completely unaware whether the database is distributed or not.
Rule 12: Rule of Non Subversion - In this rule, the database structure or database can not be modified without any change.In addition to the database language, there should not be any other rule to change the database structure.
E.f codd rules for RDBMS which makes any database as Relational Database
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database management system
database management system
A database is a complete collection of data, or raw facts, which represents an organisation’s information resource.
Like other resources, such as plant, equipment, and personnel, the information resource must be managed and maintained if it is to provide effective operational support. Since most medium to large scale organisations capture and store their data in computer based systems, database management activities are usually associated with computer processing. However, effective database management requires the classical human manager’s activities of planning, controlling, organising, and communicating. A database administrator’s position is often created to centralise these function for the automated data resource.
database management system
Database management activities involve the design, maintenance, and use of collections of data describing an organisation’s activities. These comprehensive collections of data, called databases, are usually computerized. Software called a database management system is used to enhance the effectiveness of database management by standardising data description and maintenance procedures, and by simplifying development of application software which uses the database.
The requirement for database management activities becomes greater as computer systems are asked to support the needs of analysis and decision makers at higher levels in a business organisation. This is so because of the unstructured nature of many of the decisions made at this level and because of the need of draw data together from different functional elements of the organisation.
database management system
Successful database management begins with effective database design. This design activity represents an effort to model organizational entities through data describing their activities and relationships. A three step record normalization process, which minimizes data redundancy and logical retrieval problems, is recommended as the approach to this grouping.
database management system
Database management software is available for all levels of computer sophistication, and is almost always purchased as a commercial product. Parameters for selecting an appropriate product must be evaluated in term of the needs of the purchasing organization. These parameter describe methods for defining the database, its output products and processing, its ease of use, and the degree to which the software can be integrated with other software products.
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