Approaches to using the A Bank data warehouse are divided into two methods.
The first method is a formal inquiry of pre-defined summary tables that give
general users immediate use and that provide data. The second method is
unstructured work, such as performing a search based on specific requirements or
creating a new summary table not previously defined. Super staff directly
performs such unstructured work using SQL sentences. However, sometimes a reanalysis
of the original data reveals that such data no longer exist in the data
warehouse. In such a situation, a data recovery service request (SR) is made to the
data warehouse operators and system operators, who provide such immediate
services. However, rapid response time is difficult because of the time required
and the procedures that need to be followed to process such SRs. Time to respond
to services increases rapidly if the data do not exist in the data warehouse,
creating a structural limitation. However, blindly increasing storage space to solve
this problem increases both costs and management.