You can see if you have swap enabled with this terminal command
For your reference, here is mine...
This command will also tell you...
matthew-S206:/home/matthew % swapon -s
Filename Type Size Used Priority
/dev/sda12 partition 4882428 1559124 -1
.. and again mine
As i said though, swap is orders of magnitude slower than RAM as it has to write to the hard drive but you will not get 'out of memory' crashes so much with a reasonable swap partition.
matthew-S206:/home/matthew % free -m
total used free shared buffers cached
Mem: 3522 2948 574 0 23 291
-/+ buffers/cache: 2633 889
Swap: 4767 1522 3245
If you have no swap set up then we can add one and see what difference it makes when you get memory pressure. You may find it too slow but it's worth investigating if you like.