Fast 'Find in Files' for VIM?

What are some options for getting really fast 'Find in Files' searching in VIM?

Our codebase is large enough that searching needs to work off an index. grep/vimgrep/etc are too slow.

Indexing doesn't need to be particularly fast; I can index overnight.

Thanks,

[EDIT] I'm also working in a Windows environment.

If it's source code (rather than full text search), then ctags with the TagList plugin should work well for your needs. See, for example:

http://www.thegeekstuff.com/2009/04/ctags-taglist-vi-vim-editor-as-sourece-code-browser/

EDIT: TagList and ctags will work on Windows as well (that's what I use). See the TagList install page and FAQ. The following links might prove useful:

• http://www.vim.org/scripts/script.php?script_id=273
• http://vim-taglist.sourceforge.net/installation.html
• http://vim-taglist.sourceforge.net/faq.html

There's also a TagList forum where you can get further help:

http://tech.groups.yahoo.com/group/taglist/

I set it up on my windows machine a while back, but I don't remember encountering any problems.