"=?iso-8859-1?Q?Marco_Aur=E9lio_V._da_Silva?=" <marcoprodata@gmail.com> writes:
> Running a query on 2 database-equal, with the same indices, but with
> slightly different data, I have a very different result of performance. In
> one the index is used to make the join, in another it is seqscan.
The fact that one explain includes a Limit step, and the other does not,
says that you are not really issuing the same query in both cases.
regards, tom lane