Google's John Mueller posted a short #AskGooglebot video question and answer on indexing limits. In short, like we covered numerous times before, Google does not have a limit to what it can index, but Google does not have unlimited resources to index everything. So Google prioritizes what it indexes and when it indexes it.
John said in this video "in short, no. There is no limit."
The question was "from DigitalMosaics, who is asking, is there a maximum limit to how many web pages with HTML extension-- so static web pages-- Google can index for one website?"
John responded "Well, in short, no. There is no limit."
John then dove into more detail on the two other topics in the question (1) static vs dynamic pages and (2) how indexing is prioritized.
John said:
(1) First, static pages versus dynamic pages. When content is made available to search engines, they don't know if it's from a static page. So a file that was added and has never changed or if it's created by something on the server, so a dynamic page. We can't tell, and it doesn't matter to search engines either way. Sometimes sites try to make dynamic pages appear to be static pages by adding an HTML extension, but that doesn't change anything. There is no need to do that.
(2) The other aspect is a limit for indexing. We don't have any limits for indexing. However, we do try to focus our resources in places where we think they make sense. With that in mind, our algorithms will generally try to focus indexing on pages that make sense to be indexed. So if it's a completely new website, we probably won't go off and index millions of pages. However, if we've seen that it's worthwhile, we'll be happy to do just that. This process is fully automated, so if you're building out your website, our advice would be to make sure it's awesome so that our algorithms easily understand that it's worth spending a bit more time to get it all indexed and shown in search.
Here is the video:
Forum discussion at Twitter.