If I replace sitemap with new one does it effect to my old indexs on google? Thank in advance and apologize with my english grammar if it's wrong.
Yeah why weekly? My strong belief is that if you have just a simple static site with up to 20-30 pages (like many small company websites) you simply DON'T NEED an xml sitemap... An oldish "live" page index aka regular sitemap would be just enough. Xml sitemaps are for large multi-paged websites, such as blogs, online stores, news sites, directories, online community websites etc.. (websites that due to their size can't provide easy access to all of their important pages ) If you have one of the above mentioned types of sites (with new content, news, products adding each day) you should be considering dynamic xml sitemaps, that are dynamically updated as new items appear on the site.