People who are deeper into databases differentiate between OLTP and OLAP workloads. OLTP - on-line transaction processing - mostly consists of a finite set of queries that each access a small amount of data, like you when you pay a bill at a bank. OLAP - on-line analytical processing - consists of mostly summaries of large amounts of data which can be ad-hoc, like the banker who wants to know the total transactions for the day. The two kinds of workloads are very different - so much so that some systems even periodically export the whole transaction database and re-import into a separate analytics DBMS designed for OLAP work.