Query-by-Example in Relational Database Management System

My Definition:
Give system examples, and the system returns a group of objects similar or equivalent to the examples.

Fig 1. Illustration of a QBE System

Definition in relational database camp:
In IBM QBE, Query-by-Example is defined as...

• A way of formulating query using example tables.
• User fills the example tables with values and criteria.
• Example queries is translated into domain relation calculus (DRC).
• Example of IBM QMF

In other QBE systems (Microsoft QBE), Query-by-Example is defined as a method of query creation that allows user to search for documents based on an example in the form of...

• A selected text string.
• In the form of document name
• A list of documents