Editing Data warehouse (section)

===Time-variant===
While operational systems reflect current values as they support day-to-day operations, data warehouse data represents a long time horizon (up to 10 years) which means it stores mostly historical data. It is mainly meant for data mining and forecasting. (E.g. if a user is searching for a buying pattern of a specific customer, the user needs to look at data on the current and past purchases.)<ref name=":1">{{Cite book|title=Data warehousing fundamentals for IT professionals|last=Paulraj.|first=Ponniah|date=2010|publisher=John Wiley & Sons|others=Ponniah, Paulraj.|isbn=9780470462072|edition= 2nd |location=Hoboken, N.J.|oclc=662453070}}</ref>