> Tuning is done by making sure the plan the query is using is optimized.
>
> Depending on the tool you're using you can have a look at the generated
> plan after preparing a query.
>
> Luc.

Yes, but how can I know which is the best plan for a query? (I mean "a
priori", without doing try-and-see the performance) That's the sort of
things I would like to find in the docs I'm looking for.

Thanks,

Xavi.