Question
$10.00 Dependency diagram
- From Computer-Science: General-CS
- Closed, but you can still post tutorials
- Due on Jul. 01, 2009
- Asked on Jul. 01, 2009 at 10:07:08AM
Q:
Using the STUDENT table structure shown in the figure below, draw its dependency diagram and identify all dependencies (including all transitive dependencies).
Dependency Diagrams
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- Posted on Jul. 01, 2009 at 10:21:26AM
A:
Preview: ... esented on a dependency diagram like so:<br><br>fig.1<br><br>A dependency diagram may be built up by using the following algorithm:<br><br> * Place any independent units on the graph.<br> * While there are units which are not represented on the graph:<br> o Add any units that only link to the units already on the graph.<br> o If there is no such unit, add the unit with the fewest links to non-existent nodes and note the missing links. <br><br>To create a dependency diagram for the example shown in the dependency table, we first place the independent units NewList and Length on the graph:<br><br>fig.2<br><br>Then, Copy and Search link only to NewList and Length:<br><br>fig.3<br><br>Finally, Sort links to Search and NewList:<br><br>fig.4<br><br>A few features of dependency diagrams deserve special mention:<br><br> * Recursion can be represented on a dependency diagram with a unit which links to itself:<br><br> fig.5<br><br> * A cyclic definition of some units (where, for example, a calls b, b calls c and c calls a) exhibits itself on the dependency diagram as allowing a tour:<br><br> fig.6<br><br> If the compiler being used does not support such a situation, it may be identified and eliminated before compilation.<br><br> * If the dependency diagram is disjoint or there is at most one node with paths to both of a given pair of nodes, then the system probably has poor cohesion (see [1]) and the factoring (division of the problem into modules) should be re-assessed.<br><br> * Changes to the specification of a unit, for whatever reason, often leads to a ``ripple effect,'' eventually affecting many other units. With a dependency diagram, it is easy to identify which modules will need modifying or re-testing. Only units which depend directly on the altered one should need changing (although if this results ...
The full tutorial is about 1532 words long .
Detailed Dependency Diagram for Student table
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- Posted on Jul. 01, 2009 at 11:42:37AM
A:
Preview: ... ached file. Please ...
The full tutorial is about 19 words long plus attachments.
