Textures allocating big textures

So as I’ve found there are some limitations on texture sizes, 2^27 * sizeof(texturedata)
But what to do if I want to have bigger texture?
To be more clear: I want to make texture nearly as big as my gpu ram. How can I do it?

Limitation means you can not, don’t you think ? Otherwise there would not be a limitation.
I have no other idea than allocating several textures and playing with them by yourself.