big_sitemap

https://github.com/alexrabarts/big_sitemap

BigSitemap is a Sitemapgenerator suitable for applications with greater than 50,000 URLs. It splits large Sitemaps into multiple files, gzips the files to minimize bandwidth usage, batches database queries to minimize memory usage, supports increment updates, can be set up with just a few lines of code and is compatible with just about any framework.