SEO and dynamic pages

Page cache lifetime vs SEO

[Morgenhund]

My site is built up using dynamically-generated PHP-pages. I noticed the pages are not cached by browser (I can view "page source" immediately after loading, but after a couple of seconds page source is not showable any more).

The questions:
1) Does cache lifetime affect SEO? Are such short-lifetime pages indexed by SEs?

2) Is it not better for SEO to name all pages, even PHP-generated, as '.html'?

Regards.

[isitreal]

It's not what the page is named, but the fact that dynamic pages don't return a 'last modified' type header unless you set that up explicitly, it has nothing to do with what extension, or lack thereof, that you give the page.

If you want to learn how to set that up, go to php.net [php.net], scroll to the bottom of the page, and click the 'show source' link, that will show you how to do it in a real world example, that's the actual php that runs the site pages.

As far as I can tell, it makes no difference at all in terms of SEO, I have no trouble getting stuff listed and all my stuff is dynamic, and I don't send lastmodified headers. That really only helps the search engine company as far as I can tell.

[Morgenhund]

Thank you for your answer, isitreal!