Editing Data warehouse (section)

==Characteristics==
There are basic features that define the data in the data warehouse that include subject orientation, data integration, time-variant, nonvolatile data, and data granularity.

===Subject-oriented===
Unlike the operational systems, the data in the data warehouse revolves around the subjects of the enterprise. Subject orientation is not [[database normalization]]. Subject orientation can be really useful for decision-making.
Gathering the required objects is called subject-oriented.

===Integrated===
The data found within the data warehouse is integrated. Since it comes from several operational systems, all inconsistencies must be removed. Consistencies include naming conventions, measurement of variables, encoding structures, physical attributes of data, and so forth.

===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>

===Nonvolatile===
The data in the data warehouse is read-only, which means it cannot be updated, created, or deleted (unless there is a regulatory or statutory obligation to do so).<ref>{{Cite book|title=Building the data warehouse|last=Inmon |first=William H. |date=2005|publisher=Wiley Pub|isbn=9780764599446|edition= 4th |location=Indianapolis, IN|oclc=61762085}}</ref>