I am transposing a clip to another key.  I have bounced the clip and now turning on the stretch function to enable a key change for the clip.  However I am getting a warning "this large clip will be made memory resident, do you want to proceed ?".  Appreciate it if someone can explain what "memory resident means. Thanks.
 

Ok, so I figured out what it means... essentially the clip will be in temp memory and would be erased if the PC was turned off.  In that case if I am stretching a clip so I can transpose the clip's key, and the stretch requires it to be saved as memory resident, does that mean I will loose the key change should the PC be turned off or re-boot ?  Doesn't sound right as there must be a way to save the transposed clip.  Appreciate some insight... just want to understand the "ram"ifications... get it... I made a pun there. 

My guess is...in order to perform the task you are trying to do, the entire clip must be loaded into memory. Normally project audio is streamed from disk. In this case, the clip must be read in its entirety. This could have performance implications until the operation is destructively applied to the clip.

OK, thanks for that.  More specifically, what happens to any changes I make to that clip while it's in resident memory - eg. the key change I apply to the clip, does it get saved as long as I save the project ?

I would work on a copy of the project, just in case, and apply the changes as soon as possible. Once the changes are destructively applied to the clip, the project will no longer load the entire clip into memory.