Cheap, Quick and Dirty OLTP Database Reports.
Data warehouses are a different animal.
OLTP systems are usually brought to a crawl by report processing on the server. Move processing to the analyst's desk top and save the server for doing transactions. The only way to do any reports from an OLTP database is to give the data from an SQL script in raw ascii format to an analyst. The traditional method has too much pain, i.e, have some eater-breather direct me to total a column in a report and right justify it on the page. A couple days later, left justify on the page.