Marcin Gil <marcin(dot)gil(at)audax(dot)com(dot)pl> writes:
> Tom Lane wrote:
>> I see no duplicate keys in your dump. How do you provoke the problem
>> exactly?
> Hmm.. It's enough to do 'select docid from documents where docid=0'
> and I get 3 answers (3 rows).
That's because you made "archives" inherit from "documents", so the scan
includes the rows in "archives" that have docid=0.
You could do "SELECT docid FROM ONLY documents" if you don't want the
scan to include child tables. But it's probably a bad idea to use
inheritance for the archives table at all.
regards, tom lane