And how about a lead out - maybe you'd like to try and learn something about SSDs, flash, disks, filesystems, ram, and pretty much everything else you've got wrong here before continuing?
They are not randomly writeable, unlike RAM.
RAM used for filesystems /is/ formatted. That is how it can work as a filesystem.
Formatting is just a matter of setting up a basic structure on the disk/flash/ram block so that the OS can reliably store and retrieve data. That's all - and that's all that is done with SSD's too.
Erase sectors are not usually so big, but they are still big. And write sectors are also perhaps 4K. This means you can't write less data than that - flash is not randomly writeable, in the way RAM is.
Reading and writing 4K blocks at a time sounds quite like current large hard disks to me.
It is not work of an "MMU". The SSD controller has to handle block erasing, fragmentation, re-mapping, wear levelling, etc. This will always be the case for flash (if the SSD controller doesn't do it, the OS must do it - as it does with bare-bones flash filesystems like jffs2).
It is not a challenge at all. If you are using embedded Linux, you can format, read and write SSDs just like any other media. If you are working on minimal sized embedded systems, you can use a simpler system like FAT.
MMUs are part of the system of directly accessing memory - SSDs (and other flash) is not directly accessed, and the MMU is not involved. Throwing around technical terms that you don't understand does not make you look any better.
You've pulled that claim out of thin air, without showing any knowledge of databases, filesystems, or embedded systems.
The whole point of using embedded Linux is that you can use Linux software - including databases (big ones like Postgresql, small ones like sqllite, or whatever) in exactly the same way as you would on a non-embedded Linux system.
It is fair to say that if you have an embedded system with directly connected flash (NAND or NOR), and you have a particular simple database requirement (say, a logging system), then you could be more efficient by having a simpler structure on the NAND rather than a full-blown filesystem. But that would not be an SSD.