Oct 10 2008
Physical Database Design, Hardware, and Related Issues
Understanding Application Types
In database theory, broadly speaking, a transaction is a single, atomic SELECT, INSERT, UPDATE, or DELETE. However, with regards to application types, a transaction is generally more loosely defined as a business transaction, possibly containing multiple INSERTs, UPDATEs, or DELETEs. In addition, DML truly refers to SELECT, INSERT, UPDATE, and DELETE. DML and transaction usually mean write-only, or modify-only. To distinguish the SELECT operation as read-only, the term query is used.
There are three main common application types in the world of database system applications:
1. OLTP: On-line Transaction Processing. An OLTP system is an application that contains heavy DML, transaction-oriented activity; primarily updates, but also inserts and deletes. Classic examples are reservation systems such as those used by airlines and hotels. OLTP systems can have high concurrency.
2. DSS: Desicion Support System. A DSS is typically a large, read-only database with historical content, and is generally used for simple canned or ad hoc queries. A good example of a DSS is a database behind an organization’s intranet.
3. Batch: A batch system is a non-interactive, automatic application that works against a database. It usually contains heavy DML and has low concurrency. Classic examples are production databases and operational databases relative to DWs.