Hi, I am wondering if one page(s) don't exist any more what happen s and after how long delete if delete ever? from result
It depends on a search engine. Some delete them pretty quickly some take longer. The sooner the spider bot visits your website, the sooner the cache will be updated.
Google tends to take awhile to de-index pages that no longer exist. In fact, one of my sites have pages that have been down for over 6 months now, but are still given a PR2 toolbar rank!