(PE) Groups of logically related fields which occur multiple times within a group. Periodic groups are a non-href="module.php?name=Lexikon&file=search&eid=1&query=relational">relational technique. An example of a PE would be for storing the history of a person' s name changes, where name was kept in logically related fields such as surname, first name and middle name - with the person having changed their name more than once. [Clarification?] (1995-10-30)
