RDBMS Terminology

Relational Database Management System (R DBMS). Revise definitions related to database. Database:- A database is a collection of tables, with related data. Table:- A table is a matrix with data. A table in a database looks like a simple spreadsheet. Column:- One column (data element) contains data of one and the same kind, for example … Read more RDBMS Terminology

Function Dependencies

Function dependencies are the consequence of a interrelationship among attribute of an entity represented by a relation. Function dependencies may also be due to the relationship between entities that are also represented by a relation. A relation R, attribute Y of R is a function dependencies. An attribute X of R if and only if each X value on … Read more Function Dependencies

Relational Algebra

Introduction :- Relational algebra is a collection of operation to manipulate relational. It consist a set of operation that take one or more relations as input and produre new relation as their result. The relational algebra operations can be divided into basic set-oriented operation like union, difference, intersection, cartesion product, and relational-oriented operation like join, … Read more Relational Algebra

Data Models

Data model describes the organization of different database object namely, records, data dictionary, element, etc. Three types of traditional models used for database object. There are: Relational model In relational data model, data is organised in the from of rows and column as in a table the table are referred to as relation in as … Read more Data Models

Architecture of DBMS

In the ANSI model, DBMS architecture is divide in following levels are: Internal level Internal level of DBMS is the one which is closest to the data storage refers to how data are actually stored on the physical medium such as hard disk, floppy disk etc. In internal level, complex low level data structure or … Read more Architecture of DBMS

Data independence

Definition :- Data independence is allows the database to structure changed. It means data can be add, deleted or data attributes altered with disruption to a existing system. Two level of data independence are: Logical data independence :- Insulates application program from logical operations such as combining two records into one or splitting an existing … Read more Data independence