在shelve和sqlite之间选择真正的大字典（Python）

I have a large Python dictionary of vectors (150k vectors, 10k dimensions each) of float numbers that can't be loaded into memory, so I have to use one of the two methods for storing this on disk and retrieving specific vectors when appropriate. The vectors will be created and stored once, but might be read many (thousands of) times -- so it is really important to have efficient reading. After some tests with shelve module, I tend to believe that sqlite will be a better option for this kind of task, but before I start writing code I would like to hear some more opinions on this... For example, are there any other options except of those two that I'm not aware of?I have a large Python dictionary of vectors (15