If the Increment By setting of a serialized field could be set to a calculated value it would allow increasing the entropy of a primary key without having to implement UUID.
Increment By = Int ( Random * 10 ) + 1
I'm open to the possibility that there's an important use case for this, but I don't see it yet. Entropy doesn't really make sense as an objective for a serial number field. Primary keys only need uniqueness (within a certain scope) and immutability. I only know of two situations off the top of my head where entropy is useful for a primary key: (1) the scope of desired uniqueness includes records from other tables and systems that the serializer in one table is not in control of, and (2) preventing adversaries from learning anything about your operations from a serial number sequence. Adding a calculation to the serial increment, as opposed to just using an auto-enter calculation (potentially referencing a conventional serial number), wouldn't really help either of those uses.
In the context of FileMaker, it might also be a challenge to implement a feature like this well. For primary keys, we'd want it to be impossible to create duplicate values. However, if FileMaker really gives us the full calculation engine to calculate the increment, it would be impractical to detect and reject that possibility at the time the calculation is saved.
I had thought that implementing the full calculation engine would provide some challenges exactly as mentioned.
Those two use cases were what i was thinking of trying to mitigate risk.
I think that just allowing the Increment By to be set to random in range via strict UI controls might be a more realistic solution.
As a user I want to be able to enter an integer in the Increment By box to specify the serial number increment value OR be able to set the from and to values for a random in range calculation that woulds set the serial number increment value to a random integer in the specified range.
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