On the previous post about Leonard L. Tripp’s paper, we didn’t try to extract ideas about any particular notation. Now that we specified what runtime information we should be able to annotate on ERDs, we will see some alternative notations to express order of access. To do this we will start from the slice of Basie’s ERD that corresponds to the addition of a new ticket. This example was prepared using django-devserver.
This alternative takes ideas from the sequential and parallel notations used in Rothon Diagrams and Ferstl Chart. It expresses the order in which entities, relationships and attributes were accessed considering that:
1) The same entity can be accessed several times.
2) The set of attributes accessed for an entity is not the same always.
3) Multiple entities can be accessed in parallel.
Other variations of this notation can be obtained as follows:
Alternative 1.1 (Not using numbers: top-down order)
Alternative 1.2 (Numbers inside the boxes + lines to denote parallel access)
Alternative 1.3 (Only numbers inside the boxes)
Alternative 1.4 (Numbers.Number to denote parallel access)
Alternative 1.5 (Number.letter to denote parallel access)