Is it efficient to store a moderate hierarchical object graph as a reference in a session variable? For example suppose I have an ArrayList arylistData, each row referencing an object. Is it reasonable to do this:

Session["myLIst"] = arylistData; 

Given that I do NOT have a server farm, but a single Web server, can I assume that this reference just lives in memory on the server, and retrieve the reference to it via the session variable, as opposed to the server serializing/de-serializing the entire graph on each page request/response?

 
Thanks,

Charlie Fink
 

It depends on the session State Mode,  if its InProc( the default) ,

then your arry list will be stored as a live Object ,and the session will just holds a reference to it , its the same as assigning it to a shared variable ,

Howerver, if the Session mode is configured as OOP (out of process) , then the arrylist will be serialized when its saved and decerialized when its retireved ....

in this case , you need to make sure that you are storing a serialized objects in the arrayList,

Best Regards,