Although the "postgres" user owns the "data" directory, Has he access to the whole branch of directories? Maybe the problem is that he can't reach the "data" directory.
Here owner is jme and the data dir you created must have owner jme..
The CREATE TABLESPACE schema throws this error message :
ERROR: could not set permissions on directory "/home/my_debian_account/Documents/NetbeansWorkSpace/JavaSE/Jme/database/postgresql/data": Permission denied
I have followed the web page to the best of my abilities, and AFAIK, the postgres user owns the folder 'data'.
I know that something is missing, where did I go wrong and how can I resolve this issue?