A schema is a formulation of the scheme in the language interface offered by a DBMS. As a result of this formulation not only the scheme, and therefore the conceptual schema can be represented in the computer but guidelines for creating and maintaining a conceptual data base are also laid down. In order to be [...]
The process of the transformation of conceptual schema into a computerized form is called normalization. This is referred to as the database scheme. The normalization process does not distinguish between an object set and a relationship. Therefore, it is referred to these by the relatively neutral term n-set. An n-set is a set of elements [...]
A database system is partitioned into modules that deal with each responsibilities of the overall system. The functional components of a database system can be broadly divided into query processor components and storage manager components. The query processor components are… DML compiler: DML compiler, which translates DML statements in a query language into low level [...]
There are four different types of database system users, differentiated by the way that they expect to interact with the system. A primary goal of a database system is to provide an environment for retrieving information from and storing new information into the database. Application programmers: They are computer professionals who interact with the system through [...]
The person who has the central control over the data, and the programs that access the data, is called the database administrator (DBA). Following are the functions of the Database administrator (DBA). This is one of the main reasons for using Database management systems (DBMS)s. Schema definition: The Database administrator (DBA) creates the original database [...]
The databases of any organization typically require a large amount of storage space to store their daily operational information. Corporate company’s database sizes are usually of gigabytes of data or sometimes for largest companies these databases will be of terabytes of data. 1 gigabyte is 1000 megabytes (1 Billion bytes), and 1 terabyte is 1 [...]
There are many operations carried out in any database system. Generally these several operations in any database system form a single logical unit of work. A transaction is a These collection of operations that perform a single logical function is called a transaction in a database application software. Each transaction is a unit of both [...]
There are two different types of languages to make database system. They are 1. To specify the database schema, and 2. to express database queries and updates. Data-definition language A database schema is specified by a set of definitions expressed by special language called a data-definition language (DDL). The result of compilation of DDL statements [...]
The structure of the underlying database is called the data model. This structure consists of a collection of conceptual tools for describing data, data relationships, data semantics, and consistency constraints. The various data models falls into three different groups: object-based logical models, record based logical models, and physical models. Object-based logical models Object based logical [...]
A database management system (DBMS) is a collection of interrelated files and a set of programs that allow users to access and modify these files. A major purpose of a database system is to provide users with an abstract view of the data. That is, the system hides certain details how the data are stored [...]
