Hi please add support for uploading images to MySQL instead of saving them on your website. It would be for those people who doint have a server that has a lot of memory but MySQL does and for those who have sahred host which your host would limit your memory usage please.
Topic on Project:Support desk
You should request that in a BUGREPORT.
I don't see your point in memory usage. Having files stored in filesystem consume storage (disk), but not memory (RAM). Also, having files stored in filesystem allow having CDN, although database with replication can also be used for this, but will require the MediaWiki engine on the CDN to retrieve the contents from the database.
Uploading images into a MySQL database table is a bad idea. Better invest a few Euros and get a hoster with conditions really appropriate for your needs.