> What are extents?  Do you mean display a bit of text around the search
> word to give some context of the hit?

Yes, that is exactly I meant!

> Highlighting example:
> 
>   http://swish-e.org/Discussion/search/swish.cgi

As far as I get from "swish.cgi" and corresponding "highlighting" modules -
still I have to store/copy whole file content into index and run script over
that content. No other way?