Database and Session IDs - why changed them every 5 minutes?

[eluser]deco10[/eluser]
Hi
I'm loving CI.

I want to keep track of a users session (Im using the default length). Every time they click a certain item, I want to store it in the data base so they can view it later.

I would use the session ID as they key - and possibly the time stamp to guarantee uniqueness. But if the sess ID changes, every thing goes to heck, if you get me.

How would you approach this?


Thanks!