DWH focuses on enterprise data across many subject areas
It stores large volume of data and maintains historical information.
- A datawarehouse is a very large data base (VLDB)
- Has more Subject-Oriented Areas
- A DW is a database designed to support a broad range of decision tasks in a specific organization
- Size is > 100 GB
- Running adhoc(unplanned) queries from a huge DW takes long time
DM are restricted to a single or particular subject area. Set of data marts are equal to Data warehouse.
It stores smalla amount of data and maintains aggregated data.
- A data mart is for smaller databases
- Has Less Subject-Oriented Areas
- A DM is a selected part of the DW which supports specific decision support application requirements of a company’s department
- Size is < 100 GB
- Running adhoc quries in DM allow the efficient exection of predicted queries