Why Data Warehouse Separated from Operational DatabasesThe following are the reasons why Data Warehouse are kept separate from operational databases:
- The operational database is constructed for well known tasks and workload such as searching particular records, indexing etc but the data warehouse queries are often complex and it presents the general form of data.
- Operational databases supports the concurrent processing of multiple transactions.Concurrency control and recovery mechanism are required for operational databases to ensure robustness and consistency of database.
- Operational database query allow to read, modify operations while the OLAP query need only read only access of stored data.
- Operational database maintain the current data on the other hand data warehouse maintain the historical data.