I have analysed the situation by importing multiplications of the small
and working spreadsheet. The import again slowed down and then stops at
1200 records (ui goes on with progress indicator, it does not catch the
problem). The same slowdown and stop at 1200 records happens when I show
the data in the Application. When this happens memory usage is always
between 912 and 960mb. The machine has 1gb. This prevented me from
understandig that it is a memory problem. Now I am 'sure' it is one.
I have several processes running at once, the derby networkserver,
my applications rmi server, my applications client and the ide. I
have to do the data testing with 40.000 records in the database not
only 1.200, so perhaps I should install the database server on a
remote machine to have a chance to succeed.