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Final Constraints


ORM - Checking

Check each entity can be precisely defined

Simply, populate your schema, and then attempt a few external assertions (ie. try to add some data and check where all of the parts of the update request must reside)

What you are looking for in this step is entities that don't actually exist (when you inject populations this will be obvious) - INFORMATION FLOW ANALYSIS is what this process is sometimes termed. You track what information goes where.

normally not much to do here... (that is if you have done the previous 6 steps correctly 8^)

ORM - Exotic Constraints

Add Equality, Exclusion, Subset and any other type of constraint

other constraints
  • E1's involved in R1 are not in R2 (EXCLUSION constraint)
  • Every E1 involved in R3 is also in R4 (EQUALITY constraint) - note this may be different to a MANDATORY ROLE constraint
  • Every E1 involved in R6 (subset) is also involved in R5 (SUPERSET), but not necessarily visa-versa (SUBSET constraint) - subset < superset (i.i. the subset points to the superset - this shows the line of inheritance)

The picture gets considerably complicated when MANDATORY ROLES are also included, along with sub-types

Further Constraints

ORM - Final Checks

Have one long, last look for any anomolies, then you are done.


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