18078bea9b
If we're talking to just one replica, the digest is not going to be used, so better not to calculate it at all. The optimization helps with LOCAL_ONE queries where the result is large, but does not contain large blobs (many small rows). This patch adds a digest_algorithm parameter to the READ_DATA verb that can take on two values: none and MD5 (default), and sets it to none when we're reading from one replica. In the future we may add other values for more hardware-friendly digest algorithms. Message-Id: <1479380600-19206-1-git-send-email-avi@scylladb.com>