Here are the processes which are used to load a data warehouse:
1) Extraction of data: Data which has to be loaded to a data warehouse is extracted from other databases and applications.
2) Checking for errors: Raw data is checked for data integrity and other errors.
3) Integrity of data: Non integrated data is made integrated so that it will be consistent throughout.
4) Reformatting of data: Data can be in different formats. It is reformatted to fit in the warehouse.
5) Insert and update data: After the data is purified, it is loaded in batches to the warehouse.
6) Creation of index: Index is created to find a particular data when it is required.
Process for increasing performance in a data warehouse:
1) Special index techniques: Special index techniques are used so that retrieval of data can be fast.
2) Query optimization: A query can be run in several ways. Special optimization methods are used so that computations are reduced.
3) Parallel processing: Different parallel processing techniques are used so that multiple queries can be run at the same time.