Without special tools, for example to merge many standard spreadsheets into one dataset, it is possible to do it by SQL (eg. by SELECT UNION).

There are two ways:

• Merging into the dataset.big representation, as issue Merging 2 datasets of dataset.big #4 suggested. Perhaps the simplest and ideal.

• Merge before to insert into dataset.big, when it is a temporary file with temporary FOREIGN TABLE representation.

Here, this issue, is to check strategies for the second... There are some advantage in to write specific scripts? (perhaps a non-automatic work)