Author Question: What is a view? What will be an ideal response?[br][br][b][color=green]Question ... (Read 61 times)

ashley · **on:** Jul 7, 2018

What is a view?

What will be an ideal response?

Question 2

Explain the term retrieval of analytical information in the following data warehouse definition:The data warehouse is a structured repository of integrated, subject-oriented, enterprise-wide, historical, and time-variant data.

The purpose of the data warehouse is the retrieval of analytical information. A data warehouse can store detailed and/or summarized data.

nixon_s · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

A view is a mechanism in SQL that allows the structure of a query to be saved in the RDBMS. A view, which is also known as a virtual table, is not an actual table and does not have any data physically saved. Every time a view is invoked, it executes a query that retrieves the data from the actual tables. A view can be used in SELECT statements just like any other table from a database.

Answer to Question 2

A data warehouse is developed for the retrieval of analytical information, and it is not meant for direct data entry by the users. The only functionality available to the users of the data warehouse is retrieval. The data in the data warehouse is not subject to modifications, insertions, or deletions by the end users. New data in the data warehouse is periodically loaded from the operational data sources and appended to the existing data in an automatic fashion. The data that eventually gets older than the required time horizon is automatically purged from the data warehouse (and possibly archived and/or summarized). However, the data in the data warehouse is not subject to changes. That is why the data in the data warehouse is referred to as nonvolatile, static, or read-only.