What are the recommended techniques for optimizing Magento's XML sitemap indexing?

@virginie 

Here are some recommended techniques for optimizing Magento's XML sitemap indexing:

1. Enable XML sitemap generation: Make sure XML sitemap generation is enabled in your Magento store. You can do this by going to Configuration > Catalog > XML Sitemap and setting Enable Submission to Robots.txt to "Yes".
2. Set frequency and priority: Determine the frequency and priority for pages in the XML sitemap based on their importance and updating frequency. Set these values in the respective settings for CMS pages, products, categories, and other relevant sections within Magento.
3. Exclude unnecessary pages: Exclude unnecessary pages from the XML sitemap to prevent search engines from indexing them. This includes pages like cart, checkout, search results, and filters.
4. Limit the number of links per sitemap: Keep the number of links per XML sitemap file under control. You can set the Maximum Links Per File setting in the XML Sitemap configuration to a reasonable number, such as 50,000, to avoid large sitemap files that search engines may struggle to process.
5. Split sitemap into multiple files: If the number of links exceeds the maximum allowed by search engines (usually 50,000), split your sitemap into multiple files and organize them into a sitemap index file. This helps search engines better crawl and index your site.
6. Submit sitemap to search engines: Submit your XML sitemap to search engines through their respective webmaster tools (e.g., Google Search Console, Bing Webmaster Tools). This helps search engines discover and crawl your site more efficiently.
7. Update sitemap regularly: Regenerate your XML sitemap regularly, especially after making significant changes to your website. This ensures search engines have the most up-to-date information about your site's structure.
8. Monitor crawl errors: Regularly check for any crawl errors reported by search engines in their webmaster tools. Fix any issues promptly to prevent indexing problems.
9. Implement canonical tags: Implement canonical tags in your Magento store to prevent duplicate content issues and ensure search engines index the correct versions of your pages.
10. Optimize page load speed: Maintain a fast-loading website as search engines consider page load speed as a ranking factor. Optimize image sizes, use caching mechanisms, and minimize the number of HTTP requests to improve your site's performance.

Implementing these techniques will help optimize your Magento store's XML sitemap indexing and improve its visibility in search engine result pages (SERPs).