Database Keys

Keys :- A keys is a data item that uniquely identifies a record.For example, account number, product code, customer no, are used as key fields because they identify a records stored in a database. There are different types of keys used in database. Super keys :- Super key for an entity is a set of …

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 …

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 …

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 …

Schema

Definition :- Schema indicate on overall structure of data item include their record types stored in the┬ádatabase. The first thing you must do to setup a data is to define its structure namely the schema definition. Subschema subschema refers to the application program view to the data item and record type which user would use. …

Facilities of DBMS

Data Definition Language :- It is a language udsed to define a data and their relationships to other types of data. Data definition language used to create file, database, data dictioneries and table within the database. DDL also define the format or scheme of the database. Data definition language allows specification following information about the …

Database

Definition :- Database is a organized collection of data that are related in meaningful information, which can be accessed by different user but stored only once. Application of database You needs to certain operation which help to the maintain data in database. The most common operations performed on database are: Insertion :- This operation add …

Introduction of Data

Data Data is row material that are used as input and information is processed. Data obtained as output of data processing. Data can be represented in the various form i.e. in figures, characters, symbols, pictures, audio. etc. Information Information is the manipulation of data. In other words, information is the summarization of data in a …

Spreadsheet

A application software that can create professional looking visual aids called presentation graphics software. Graphic object is a written or diagram representation like graphs, figures and diagrams slides can also form the basis of web-casts. Most popular graphics multimedia and presentation package are: Power-point etc. Uses of powerpoint Power-point can create various presentation like, charts, …