I have a MacBook Pro from 2011, and Mac OSX 10.8.4 with 8 GIG of RAM.
The running program is MAMP and Dreamweaver.
I have a third party application called Memory Clean as system software. With this program I can see how much RAM is used, and this is not much. However, the longer I use the Data Assist, the fans running, and the CPU is used more.
I have to save the preset for every step I make, if I move a column up or down.