Data Warehouse Essay

Question 1 – What is a Data Warehouse? Mention its advantages.

Answer -

According to Bill Inmon, who first coined the term data warehouse, a data warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data which supports organization's decision making process. By another definition, "A data warehouse is a copy of transaction data specifically structured for query and analysis."

Subject-Oriented: The Data Warehouse is Subject Oriented in nature because it provide us the information around a subject. It can be used to analyze any particular subject area. For example, product, customers, suppliers, sales, revenue etc.

Integrated: A data warehouse integrates data from multiple data sources. Data

Warehouse can be

Once data is entered into the data warehouse, it will not change. Because data warehouse is kept separate from the operational database, therefore frequent changes in operational database is not reflected in data warehouse and historical data in a data warehouse is/should never be altered.

Advantages of data warehouse:

Enhanced Business Intelligence:

Data warehouse provides data from various different sources which enhances decision making process of managers and executives of organization and this they are not dependent on their limited data or on their guesses. Data warehouses can be integrated with related Business intelligence and can be applied directly to business processes such as inventory management, financial management, and sales etc.

Time savour:

Data warehouse provides quick access to critical data from heterogeneous sources all in single place. This helps business users to rapidly make critical decisions on key initiatives. Theirs precious time is not wasted in retrieving data from multiple sources.

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Also data warehouse helps business executives query the data themselves with little

Both data mining and data warehousing, being business intelligence tools, turns information (or data) into actionable knowledge. It is methodology and process which sets a distinctive line between these two tools. Analyst usually develop a hypothesis and then use technical tools to query and sort through terabytes of data looking for patterns to prove or disprove their theory. Business executives then use this information to make better business decisions. Data warehousing is a process that occurs and must occur before the process of data mining can take place, because data mining is the process of extracting meaningful data from the common database which data warehousing has compiled and organized from myriad sources. Data mining aims to examine or explore the data provided by data warehouse using queries. Data mining triggers queries on the data warehouse. Exploring the data in data mining helps in reporting, planning strategies, finding meaningful patterns etc. e.g. a data warehouse of a company stores all the relevant information of projects and employees. Using Data mining,