Tom Lane wrote:
>
> Hm, it sure looks to be exactly the same plan. The performance
> difference seems to be just that the seqscans are faster. I surmise
> that in the 7.3 database you had a lot of dead rows, or at least a lot
> of free space. Possibly you need to vacuum more often to keep down the
> amount of junk in the tables.
The two databases were created from scratch and the first
operation on it ( after a vacuum analyze ) was just that query.
I will try to pump up the statistic target.
Regards
Gaetano Mendola