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 <tgl@xxxxxxxxxxxxx>:
"Tomas Vondra" <tv@xxxxxxxx> 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
