Late Travel company (LT) Research Paper Example | Topics and Well Written Essays - 4750 words

Late Travel company (LT) - Research Paper Example DBMS uses various models including relational model. DBMS utilizes query language to get information. A query language can analyze and update data. It takes care of the security of the database. Unauthorized users are prevented from viewing, updating etc of the database. Modeling language, query language, data structure and transaction mechanism are the main parts of DBMS.With the help of 'Data Manipulation' subsystem the user can add, delete or change information in a database. Relational Databases are so popular in that they are the absolute choice for storage of financial records, logistical information, manufacturing in formation, personal information etc. The software is Relational Database Management System. (RDMS) Constraint restricts the domain of an attribute and also the data to be stored in relations. . SQL makes use of 'check constraints'. There are also domain constraints as every attribute has a related domain. , Normalization is an integral part of relational model. It checks duplication of data and simultaneously loss of data integrity. The Relational Model has three parts. Structures are objects which store the data. Data has to remain the same during all the operations. It should not get disturbed during transfer, storage and retrieval. Data Integrity takes care that the data will always be consistent, correct and accessible. It remains faithful to its source. Referential integrity is the mos... It checks duplication of data and simultaneously loss of data integrity. The Relational Model has three parts. Structures are objects which store the data. Operations manipulate the structure and the data it contains. They follow a set of rules. Integrity rules decide the operations on the data and structure. In fact it protects both. Data has to remain the same during all the operations. It should not get disturbed during transfer, storage and retrieval. Data Integrity takes care that the data will always be consistent, correct and accessible. It remains faithful to its source. However in the internet, the data is broken into packets, before being transferred. Data integrity ensures that, even then the data is put back to shape and recovered. Data integrity can be disturbed by malfunctioning of hardware, attack of software applications by viruses. Human error in data entry is another cause. Referential integrity is the most common. In this, the errors in the relationship between a foreign key and primary key are avoided. Proper use of integrity constraints will prevent end user from writing invalid matters. Also unauthorized persons cannot alter the data. 'Server enforced data integrity' is the most dependable data integrity. RDBMS is considered the authority to accept or reject data. Normalize: It is advisable to normalize the database while designing a relational database. Normalizing to 'Third Normal Form' is always recommended. It means, the attributes in each table should depend on the key. Normalization takes care that errors in data input at are reduced. It removes excess data from records. Data model is an integrated collection of concepts for describing relationship between various data, constraints on