It seems that the size of the data file makes this problem...
I can export a small one.
Anyone knows how to resolve it?
Thanks in advance.
I'd guess you're using phpMyAdmin and running up against the timeout parameter. You can adjust this parameter in your php.ini file.
Alternativly,
I find that making my own script, that outputs the data in a CSV format, works even better. I adjust the 'for' statement to do it in blocks of XXX amount.