SESSIONS vs. MySQL

Hi all. Let me start out by saying, I have STFW and read through the list archives. Now that that's out of the way. To speed up our application, we want to implement using SESSIONs in some locations. Beforehand, on every page, we would run approximately 30-40 queries just to get the page setup - user information and other stuff. Now while we can't take away all of the setup queries, we would like to reduce the startup number. Ok, so I've implemented this in several places where information basically does not change from page to page. Jumping to the point/question... when does it become more inefficient to store lots of information in SESSION variables than to run several more queries? Note, we are actually storing sessions in the database - so a read/write is required on each page load - it's not file sessions. Now I know this can depend on the complexity of the queries and how much data is actually stored inside the sessions... but initial thoughts? To give you a number, the strlen of the _SESSION array is 325463 - which is equivalent to the number of bytes (I think). Thanks, ~Philip