Best practices for efficiently storing md5 hashes

问题:

Possible field types:

BINARY(16)
CHAR(32)
BIGINT + BIGINT

How do I decide which one to use?

回答1:

If the column is indexed and you know what you're doing, BINARY(16) for performance reasons.

Otherwise, CHAR(32) is fine. Make sure the column uses the ascii charset though. (ascii_bin for example)