I had to make my first sitemap, which is an XML document that tells search engines what pages to scan. The site has over 150K pages, so doing this manually was not an option. My next thought was to use an inexpensive program that periodically scans the site, and automatically generates new sitemaps. Despite the convenience, these programs were not easily customized, and required impossible-to-authorize server modifications. I'm glad these barriers existed, as the solution was writing a script that got me acquainted with SimpleXML.
Instead of scanning the entire site, a small amount of URLs are entered manually, and the rest were populated based on database results. Using database calls instead of crawling through files means it's a faster process that gives me more control over what the map includes. Because a sitemap is limited to 65000 entires, I made sure that the script generated additional maps before the current ones reached capacity, then rendered an index that referenced every map based on how many were created.