Databases
Visual Representation
Collected by Xiaoying Tu — Garcia-Molina, H., Ullman, J., & Widom, J. (2009). Database Systems: The Complete Book. 2 ed. Prentice Hall Press, Upper Saddle River, NJ, USA.
Query languages (basic)
Within-Database
Visualizes the operations of a query involving joining two relations by an equality condition between two attributes in separate relations, which helps reader understand the logical process of such queries
| Symbol | Concept |
|---|---|
| rectangles | tables / relations |
| horizontal stripes | rows |
| circled portions within the stripes | specific attribute values in those rows |
| double-sided arrow | equi-join condition |
The relevant components in both relations and the checking conditions involved, particularly the equi-join condition linking records in separate relations
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A notional machine is a pedagogic device to assist the understanding of some aspect of programs or programming. To something along the lines of A notional machine is a pedagogical tool designed to support the understanding of programs, programming, and other aspects of computing such as databases.
