How to show new forum posts

[jasondavis]

On pretty much any popular forum package, it will show users unread threads, even this forum does it, I am wanting to know how I can add this feature into my custom forum. How does it work exactly on a forum like phpbb or vbulletin, performace is very important on my site so I was thinking maybe these forums do it with out storing extra data in the DB for read/unread.

Please give me any advice if you know how this function works.

[dagon]

add a table with user and message id, either add all users for each new msg and delete once read (less space) or store that they have read a msg. To see how any particular open source forum does it, download it