Hello and thanks for reply!
Im on Linux, Litespeed web server, PHP 5.2.17, MySQL 5.5.34
i tried with PHPMyAdmin and this is the result:
for all tables it says: "note Table does not support optimize, doing recreate +..."
i Googled and came to http://dev.mysql.com/doc/refman/5.1/en/optimize-table.html
especially the paragraph referred to "For InnoDB tables, OPTIMIZE TABLE is mapped to ALTER TABLE..."
In PHPMyAdmin i checked and the type of WP Tables are InnoDB.
I have other WordPress db istances that are type MyISAM and if i run the optimize sql query it works fine.
So this is the "problem" and maybe why WP-OPTIMIZE doesn't affect.
How i can do? Should i contact the web hosting or there is another SQL query i can run to optimize?