I’m planning on implementing a transactional (ACID) key-value storage on modern hardware, i.e. SSD and large RAM. The technical choice on question is the type

I’m planning on implementing a transactional (ACID) key-value storage on modern hardware, i.e. SSD and large RAM. The technical choice on question is the type of index storage to use: b+tree, extending hashing, or linear hashing. There will be an appending WAL for batching the writes and for transaction support. A single checkpoint worker will apply the updates from WAL to the index storage periodically. The updates will be batched, to minimize the random seeks. Please help me evaluate the three indexing approaches, on the criteria of fast read, fast write, cache friendliness and ease of supporting atomic update during checkpoint.