Idea of Add Database Icon
It's a drawing of a cylinder that is divided into three short cylinders stacked directly on top of each other. It's like the shape of a three layer cake. There is a plus sign inside of a circle that is placed over the bottom right of the cylinder to indicate, "add database."
This is a Add Database icon. It is available in PNG and vector. Downloading is free for PNGs up to 100x100px.