August 2002
Intermediate to advanced
528 pages
10h 12m
English
A data warehouse consists of a series of tables that hold the data from an OLTP system. Data warehouses’ characteristics include the following:
The data is not current. It may be only minutes older than the production data. It may also be considerably older, as in the case of historical data. Some data warehouses keep data for years. This data are used to compute trends or other types of analysis.
The data are used to produce business information.
Unless you are a developer, you will be executing your SQL against a data warehouse. DBAs think that executing SQL against a production system for the creation of business information will degrade the performance of the system. Production OLTP systems are used in the day-to-day business ...