Sorry for the way this patch is presented lem9, but the rules on the proxy on the company are so dacronic that I couldn't for my life connect to the repository.
This patch gives the user the option, via a new global variable to choose if, when generating the PDF_SCHEMA, they will show all the fields on the tables, or only the keys.
By keys here, the code gets every key on the table, and get the name of the field it uses, for multi-field key, it gets the onw with sequence_index = 1;
The txt file is the patch to the pdf_schema.php file. I'm still trying to make the SVN work, if I find some way I will make a diff\patch
NEW GLOBAL VARIABLE
$cfg['ShowOnlyKeys']= default FALSE
If = TRUE than it shows only the keys, if FALSE, shows all fields