Given:
----------------------------------
vin | driver | is_owner
--------------+--------+----------
231431cxzv87 | bob | true
231431cxzv87 | jeff | false
231431cxzv87 | greg | false
32342klj234s | jeff | true
Is there a way to add a constraint so that there is only one owner per vin?
Edit: I found this question .
Is adding a partial unique index meant to suit this purpose?
Yes partial index is your choice.
create unique index unique__vin on table (vin) where is_owner;
Here index covers only rows where is_owner is true and withing this rows vin should be unique.
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