What is a Data Warehousing?

Datawarehosing is a process of creating,queriring and populating datawarehouse. it includes a number of discrete technologies like  
Identifying sources 
Process of ECCD, ETL which includes data cleansing , data transforming and data loading to targets. 

A Data warehouse is a subject oriented, integrated, time-variant, nonvolatile collection of data to enable decision making across disparate group of users.

A data warehouse is a repository containing subject-oriented, integrated,time-variant and non-volatile collection of data, used for  companys decision support systems requirement

Datawarehousing is a subject oriented, authoritative,integrated historical database reflective of changes over meaningful time periods in order to facilitate query and analysis for useful management decision making.

Datawarehousing is a subject oriented, authoritative,integrated historical database reflective of changes over meaningful time periods in order to facilitate query and analysis for useful management decision making.

Datawarehouse contains a collection of historic(history of data) ,integrated ,non-volatile  data ,which is used for analysing and developing forecasting reports.

Data-Warehouse-Prozess (englisch data warehousing) ist der Prozess zur Bewirtschaftung und Auswertung eines Data-Warehouses, der die folgenden Schritte umfasst: #Datenbeschaffung: das heit die Extraktion der relevanten Daten aus den Quellsystemen, Transformation und gegebenenfalls Bereinigung der Daten (Data Cleansing) in einem Arbeitsbereich (englisch staging area) sowie Laden in das Data-Warehouse. Dieser Schritt wird auch Extract-Transform-Load-Prozess (ETL-Prozess) genannt.

Cheers,

Sithu

a subject oriented,time varient,non volatile and integrated decision supporting system.

Data Warehousing is a collection of Subject Oriented, Integrated, non-Volatile and time Varient to Support Management decision-making Process

A single complete and consistent store of data obtained from a variety of diff sources made available to end users in what they can understand and use in a business context.
As per bill Inman - a collection of subject oriented, integrated, nonvolatile and time varying data which is used in the process of decision making.
As per Ralph Kimball - a copy of transactional data specially structured to query and analysis.
In layman words - a data warehousing is a read only database which copies and stores the data from transactional data.

Data Warehousing is Relational Database which is specially designed for analysis processing rather then for querying and transactional processing.

As explained by users , i think DWH is repository containing subject-oriented , integrated , nonovalatile and time varient data which helps the management to analysis the business trends and take the appropriate decision to improve the business.It is important that data quality is good inorder to analyse the data and take appropriate decision. It also helps to anaysis how a particular product is doing in market and take appropriate decision to improve more.

Data warehouse is Subject oriented,Integrated Non volatile, Time variant collection of data. unlike transactional systems. Its a Denormalized huge database.Used for Querying and Reporting Analytics.

Hi..!!
As explained following above different people have different definitions for a data warehouse. The most popular definition came from Bill Inmon, who provided following:
A data warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data in context of management's decision making process.