How often does GWT check dynamic sitemaps?

Question

I'm working on a fairly large site, that generates a dynamic sitemap hourly. Now in Google Webmaster Tools the sitemap isn't submitted yet and I'm shying away because I'm afraid that the new content (which appears in the dynamic sitemap) won't get crawled as quickly. So my question is: How often do the GWT check the sitemap once submitted?

Any other thing I should be aware of when working with GWT and dynamic pages?

P.S. I checked this thread How often are sitemap.xml checked for updates by crawlers? and from what I understand Google crawls more often when the site gets updated regularly - but does the same apply for the GWT?

Answer 1

The fetching of sitemap files is actually performed by googlebot. The frequency of fetching sitemaps appears to be governed by pagerank and change frequency, similar to how other urls are scheduled for re-crawl.

I have several sites with sitemap ranging in PR from two to five. Googlebot appears to fetch the sitemap files between once a month and six times a month. My sitemaps are rarely updated (less than once a month on average).

In any case, submitting the sitemap should only help. If Googlebot does find new urls to crawl in the sitemap, it should do that crawling right away. If it doesn't find the urls in a sitemap, it will crawl them just as quickly as it would have otherwise.