Thank you very much for the insights (and how to read correctly a explain :)). There is a difference in data between the 2 databases, crons where running on one and not the other.
But your insights enabled us to dive deeper, thanks ! 2014-11-05 18:30 GMT+01:00 Tom Lane <t...@sss.pgh.pa.us>: > "Tomas Vondra" <t...@fuzzy.cz> writes: > > Dne 5 Listopad 2014, 18:10, Tom Lane napsal(a): > >> For some reason there's over 1000 times more rows in andalertsmatch in > >> the 9.1.14 installation. I'm betting on a foulup somewhere in the data > >> dump/restore process. > > > I'd bet that's mostly due to rescans in the merge join ... > > Doh, I should have thought of that :-(. But still, the difference in > the number of final output rows is pretty compelling evidence that > it's not really the same data. > > regards, tom lane >
