Changing frequency
You can set the <changefreq> tag in your XML sitemap to tell Google how often a page will be updated with new content. This tag refers only to code or text, not images.
Never: The content on this page is static and does not change. You can use this tag for news articles, press releases, and similar content.
Annual: Use this tag if you have an annual event, sale, or report.
Monthly: This tag might be best suited for FAQ pages, monthly reports, or blogs that are only updated once a month.
Weekly: You can use this tag for product pages, a weekly blog uae mobile database page, or a "week in review" newsletter.
Daily: This tag is best suited for news pages, message boards, and blog posts.
Hourly: Major news sites use this label for things like weather updates.
Always: This tab is for stock market pages, Twitter feed pages, and similar web content that is constantly refreshing.
Avoid No-Index Pages
When you submit a sitemap to Google, you are asking that your site be crawled and indexed. If your pages are marked as "noindex", they should not be submitted in the sitemap file.
Avoid duplicate content
Sometimes you keep duplicate content for archival purposes; for example, if you update a document, you might go to a previous version of the document. However, Google penalizes duplicate content, so you should set the duplicate pages to "noindex."
Using multiple sitemaps
If you have a large website, your sitemap may become too large to upload. The maximum size of a sitemap file should be 50mb or no more than 50,000 URLs.