Hi, Most of my sites has duplicate content problem since pages are indexed both like domain.com/xxx.php?q=123 or domain.com/xxx-123.html or with PHPSESSID. Because of this problem they are all removed from search engine results. I guess sth like duplicate content penalty. I'm asking the best way to solve this problem. My sites have thousands of pages indexed in google. For example can i remove one of site completely from google and have it indexed again without the duplicates?
If all pages are being removed, the problem might not be duplicate content. When I have duplicated pages, one of the duplicates always remains in the index.
but you cannot remove your site from google index. close it for spidering for a few days, make you changes and then reopen it. you may close it from robots.txt