Re: [GENERAL] looking for a globally unique row ID

>> Isn't this typically handled with an inheritance (parent-children)
>> setup.  MasterDocument has id, subtype and any common columns (create
>> date etc) then dependents use the same id from master to complete the
>> data for a given type.  This is really common in ORM tools.  Not clear
>> from the description if the operations could be similarly handled
>> (operation id, operation type as master of 17 dependent
>> operationSpecifics; there is also the "Activity Model")
> I do that, but may be I do that badly.
>
> Currently I do have 6 levels of inheritance which partition my
> document-class space. But I cannot see any way to have a unique index
> (unique constraint) to cover all those partitions at once.
>
> This is actually the core of my question: How to make one?

I cannot image a single postgres index covering more than one physical 
table. Are you really asking for that? Remember each dependent record 
has an entry in the master so the master guarantees a unique set of keys 
across all the dependents.  Now if you have enough documents you may get 
into partitioning but that's a separate issue.
How you model the work done on (or state transition of) those documents 
is a yet another design, but at least the work flow model can safely, 
consistently refer to the master table.




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