Ans: A Data warehouse is a subject oriented,
integrated ,time variant, non volatile collection of data in support of
management's decision making process.
Subject
oriented : means that the data addresses a specific subject such as sales,
inventory etc.
Integrated
: means that the data is obtained from a variety of sources.
Time
variant : implies that the data is stored in such a way that when some data is
changed.
Non
volatile : implies that data is never removed. i.e., historical data is also
kept.