[development] fancy URLs for SEO (Was: Caching, caching, caching...)

[Jakub Suchy]

> that would be a complete nightmare for issue nodes, since the titles  
> can change all the time, yet people need easy to paste, unique URLs  
> to refer to issues with.

Hi,
starting new thread as i believe there is another issue.
fancy URLs are not suitable for users only. they are designed to be good for
search engines (SEO) too.
Drupals approach to fancy URLs is one of the best between CMS. But there
are some drawbacks:

1) it allows duplicates. a duplicate URL for same content is nor good
for search engines neither for users.
2) also node/123 has an alias "my-test-node". mysite.com/my-test-node
displays correct content, but mysite.com/node/123 displays it too. this
is duplicate again. maybe this is a part of the solution?

displaying: http://example.com/node/123:
if (alias_exists("node/123")) {
  ... redirect 301 moved permanently to alias ...
} else {
  ... display content ...
}

we should also remember: when redirecting to new alias, we should
everytime do 301 redirect, not ordinary PHP's Location:, which is 302.

any ideas how to solve 1) ?

Jakub Suchy