Hello everybody, I'm currently developing a plugin regarding virtual inventories. I need a efficient way to save (possibly) a lot of inventories. I already have a working version of the plugin: a object containing a HashMap, containing player names as the key, and as the object another HashMap with an Integer as the Key and a object containing the inventory contents (in which every item is stored with CardboardBox, for which I have also submitted a bugfix in the official topic). So, this works, but in a production scenario where there can possibly be hundreds of chests, this will use up a lot of RAM. So I looked up on the Internet for a embedded object-based database, but this looked a bit an overkill to me. I'm asking, to anyone which has experience in maintaining a database of inventories, how can I do this. Some additional information: the inventories need to be accessed by player name and chest ID (which is unique only to the player but there can be infinite chests with ID 1, for example). Thank you!