So SSI can only benifit static files?

http://en.wikipedia.org/wiki/S开发者_如何学Pythonerver_Side_Includes

For dynamic contents, I don't see any benefit of SSI,is that the case?

SSI is an old technology. It came out before ubiquitous integration of dynamic languages (e.g. PHP, ASP.NET, etc) and when web-hosting was relatively expensive, slow, and otherwise limited.

There is nothing that SSI can do that an independent "fully dynamic" environment can't. Remember that SSI is itself a very small "dynamic" content module with only a limited set of directives. When CGI was the only connection method SSI had some performance advantages over the domain of tasks it could do. However, better web-stacks -- and faster/cheaper servers -- have largely supplanted any advantage.

Historically, it required hacks to even get SSI to handle dynamic content just due to the architecture of Apache and mod_include, etc. (I am not sure if the situation has improved, but I can only imagine it is not advisable to mix the two.)

Happy coding.