Running PHP with Views Caching

I want to use views caching(Views content cache) on a view which lists nodes by title, body, and a Global: PHP field. The php field assigns a search rank to each node based on a query from the current url(ex: http://www.site.com/search=new+train+station).

However, with views caching enabled, the php snippet isn't executed and all the nodes have a search rank of 0 by default without regards to the query from the url.

Now, I need the caching enabled as my view would take too long to load otherwise. How can I enable caching without stopping my php field from rendering an accurate output?