hi memory usage with php-cli

Hi, I have a huge xml-file with about 500k lines, which gives around 17000 products, which I import to a database. The problem is that the script is taking a lot of memory, about 100mb when it's finished. The script goes something like this $product = array(), then I add some values to the array, name, art.no, and when the product is done, I do $product = array(), and do the same thing over and over. Is there any way to configure php/zend to use less memory? I've tried #define ZEND_DISABLE_MEMORY_CACHE 1 which doesn't help. best regards Robin