Administrator's Guide

defines.inc.php file
Among other constant values, this file contains the location for all files and
folders. If you need these changed, do not forget to keep the original at
hand, in case you wish to go back to the original path.
smarty.inc.php file
 $smarty->caching = false;: Smarty's cache system must be disabled
because it is not compatible with PrestaShop.
 IMPORTANT: in production mode, $smarty->force_compile must be
set to "false", as it will give a 30% improvement on page load time.
On the other hand, when editing a .tpl file, you will have to delete
the content of the /tools/smarty/compile folder (except index.php) in
order to see the changes live. Note that this setting can also be
done in the back-office, in the "Preferences" > "Performance" sub-
tab, in the "Smarty" section.
 $smarty->compile_check should be left to "false".
 $smarty->debugging gives you access to Smarty's debugging
information when your pages are displayed.
Improving PrestaShop's performances
Here are a few tips that should enable you to optimize PrestaShop.
 Enable MySQL's cache (or ask your web host to do it for you), and
give it a high value (for instance, 256M).
 Do not forget to put the $smarty->force_compile to "false" when in
production mode, either via the smarty.inc.php file or the back-office.
 Whenever possible, use an opcode cache (or ask your web host to
install one for you), in order to alleviate the server's processing
load. PrestaShop is compatible with eAccelerator. Opcode means
"operation code", and defines the compiled state of the dynamic
files, which can processed faster.
 If possible, split your static elements betweens different domains
and sub-domains, in order to get parallel HTTP connexions. To put
that in place, open the /config/defines.inc.php file and add these
lines (adapted to your needs):
if ( $_SERVER['REMOTE_ADDR'] != '127.0.0.1' )
{
define( '_THEME_IMG_DIR_', 'http://img2.xxx.com/' );
define( '_THEME_CSS_DIR_', 'http://css.xxx.com/' );
define( '_THEME_JS_DIR_', 'http://js.xxx.com/' );
define( '_THEME_CAT_DIR_', 'http://img1.xxx.com/c/' );
define( '_THEME_PROD_DIR_', 'http://img1.xxx.com/p/' );
define( '_THEME_MANU_DIR_', 'http://img1.xxx.com/m/' );
define( '_PS_IMG_', 'http://img1.xxx.com/' );