The data warehouse is designed for strategic decision support and is largely built up from the database that makes up the operational database The basic characteristic of a data warehouse is that it contains a vast amount of data, which can mean billions of records. There are some specific rules that govern the basic structure, of a data warehouse. One of them is, iris nonvolatile. According to this, the data warehouse is always a physically separated store of data transformed from the application data found in an operational data environment. Due to this separation, a data warehouse. does, not require transaction, processing, recovery, and concurrency control mechanism.
It usually requires only two operations in data -accessing. initial loading of data and access of data. it Means that data In a data warehouse is never updated but used only for queries. Thus such data can only be loaded from another database such as operational databases End-users who want to update data must use the operational database, as only later can be -updated, changed, or deleted. This means that a data warehouse. will always be filled with historical, data.
Hence we can say that “A-data warehouse is built on historical data and is not guaranteed to be up-to-date information”
