URL Rewriting – Is it really necessary?

In the past, Search Engines including major ones like Google, Yahoo and MSN had hard time understanding and indexing pages that are dynamically generated. In such dynamic pages, a single page can deliver multiple page contents depending upon what the user has input. For example, the dynamic url http://www.xyz.com/abc/def.asp?x=12&y=adf&z=45 delivers one page content while http://www.xyz.com/abc/def.asp?x=2&y=adf&z=34 delivers completely different content even though both of these links are using the same file ‘def.asp’. Search Engines in the past were not smart enough and thus would consider both these links as one file and indexes just one. However, SEs now can understand and parse all these types of links regardless of their complex structure with querystrings. It is considered that all major Search Engines can now handle dynamic urls up to 3-4 querystrings. So, you will be okay and be assured that your site will be indexed properly even if your site is dynamic. However, static pages are always good over the dynamic pages. So, why not take the advantage of static pages by URL rewriting? URL Rewriting, Mod-Rewrite in Apache server, is the process to convert dynamic urls to static urls. By having static urls, you will make the urls friendlier and easier for end users, In addition, static urls I think rank better in search engines than dynamic ones.