Can the chainstate folder from a pruned node be used with the blocks folder from a full node to provide the full blockchain? Assume that both nodes have been running for months.
If the blocks folder contains references to filenames in the chainstate folder, then the answer is no. I know this because the filenames in chainstate on the full node are different from those on the pruned node.
If, on the other hand, the chainstate folder stands as a self-contained and full record of the UTXO Set including all pointers, filenames, and identifiers required to interpret it, then it seems that I will NOT need to import chainstate from the full node to the cloud server.
Bonus question! Out of curiosity, there's another question here that doesn't affect my situation, but it would be nice to understand why the answer is no if it's no. If the chainstate folder on a full node got corrupted, could the chainstate folder from a pruned node be dropped in to recover?
Both the blocks and chainstate folders reflect a block tip, and if the two folders reflect different block tips, they will be incompatible. I should have made it explicit that the question assumes that the two different sources of folders would both be synced up to the same block height.
An interesting edge case is what happens if they are using the same block height, but the blocks they used at that height are two valid but different blocks.