Hi,
I would go with this solution:
- have all your png inside your Project under Resources. then they only get loaded on demand ( search for Resource on the Ecosystem and learn about Resources on Unity docs)
- maintain a strict naming conventions for your resources path and file names,
- in your database refer to these images using that convention ( maybe just the name, or maybe the path as well, it depends how you organized it, but the less the better).
- then you never deal with the images during your logi, you deal with a reference to them images, and then at the very last moment you simply load that image from resources and use it visually.
Does that make sense?
bye,
Jean