Notes with worthy tutorials
Data Definition Language (DDL): The specific language used to express the database schema by a set definitions is called Data Definition Language (DDL). The DDL is also used to specify additional properties of the data. Another special type of DDL, called the Data Storage and Definition Language, is used to specify storage and data access … Read more
Database Language: As whatever we want to be manipulated by computer has to be written using specific language, database is not beyond them. To write or create database management system we use database languages. They are of two types; Data Definition Language (DDL) and Data Manipulation Language (DML). DDL is used to design a database … Read more
Data Model: Data model is the structure of the database, which is a collection of conceptual tools for describing data, data relationships, data semantics and consistency constraints. The data models can be classified into the following four categories. Relational Model: The relational data model uses a collection of tables to represent both data and the … Read more
Instances: A database is generally used by many users where insertion and deletion of data occurs frequently. Overall information stored in a database at a particular moment is called the instance of the database. Schemas: The overall design of a database which includes the data structures, table designing and relation of data from table to … Read more
Data Abstraction: Different users require different view of the database which is useful and necessary to them. This is data abstraction by which we abstract useful data from a database for a particular type of users to use. There are 3 levels of data abstraction, those are as follows; Physical Level: The lowest level of … Read more
Disadvantages of File Processing System: Keeping organization information in a file processing system has some disadvantages including the followings, Data Redundancy & Inconsistency: As the files are created by different programmers, there is a huge chance of data redundancy which is responsible for unnecessary storage and access cost. This may also lead to data inconsistency … Read more
Applications of DBMS: DBMS is getting used in many places. Everything from file cabinets to dictionaries is disappearing from today’s working place, because it is easy to make use of the data using a DBMS. The uses or applications of DBMS include the following, In Banking: For customer information, accounts, loans and banking transactions. This … Read more
Database: A database contains a collection of related items or facts arranged in a specific structure. The most obvious example of a non-computerized database is a telephone directory. DBMS (Database Management System): A database management system is a collection of interrelated data and a set of programs to access those data. It allows people to … Read more