>> Merge Left Join (cost=9500.30..101672.51 rows=2629549 width=506)
> And the query does not return data though I have been waiting for > 10 mins. > > Do you have any idea ?
Unless you use a cursor, PostgreSQL interfaces typically don't show any response on the client side until all rows have been received and cached on the client side. That's estimated to be over 2.6 million rows in this case. That can take a while.
