• robyoung@beehaw.org
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    2 years ago

    I don’t understand why the most_recent field is needed. Surely the most recent state can be derived from the order field and the unique constraint on it can prevent concurrency issues if the previous sequence is taken before the state change. The benefit would be that the transition history table could then be append only.

    • ck_@discuss.tchncs.de
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      2 years ago

      Yeah, I’m wondering that too. Also, why would a transition ever be updated? Should a successful transition not be a write-once operation? I guess it boils down to the finer details of the requirements of the application.

      • towerful@programming.dev
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        2 years ago

        I think the most_recent is to power the unique index constraint. This “powers” the whole thing.

        Whereas the sort_order is to allow easy sorting, which is just for human readability. You could argue that you can rely on the “created_at” for this.
        Considering the examples increment it by 10, I assume this is to allow admins to manually override a sequence or force a data consistency thing or whatever.