Testing memory usage with my loaded remastered live DVD of Debian-Mate.
By running FF, Caja, and VLC playing a movie file from my hard drive; my memory usage went nearly to 1.5 Gb. I bet I could run this memory usage up to 2 Gb fairly easily.
Not an issue where I have 4 Gb; it is unlikely I would come near to using 4 Gb, so no swap partition is needed and only a small swap file would be needed; if software expects to see a swap.
Using this data I will make suggestions for the installer and for running the live DVD.
If a computer has 4 or more Gb ram, then only a small, almost symbolic, swap file need be created. Do not bother to search for a swap partition for running live nor for installations.
If 2 to 4 Gb ram, create a larger swap file for the install, say 500 Mb. Running live may be ok with 2 Gb??? but search for and use a swap partition, if exists, just in case.
If 1 to 2 Gb of ram, search for and mount a swap partition, both for running live and during installs. If no swap partition is found, create a 1.5 Gb swap file for the install. Running live may fail if only 1 Gb ram, with no swap partition.
If under 1 Gb of ram, automatically search for and mount a swap partition, both for running live and for installations. Without a swap partition, running live DVD is very likely to fail. Installer should mount and use a swap partition of 2 Gb, or create a swap file same size, if no swap partition is found.
Something like this could be used for rules to automate the installer, to ask less questions, and be certain to have sufficient memory.