Data type for protobuf objects in mysql
BLOB is correct, as that is a binary string. TEXT is a character string, but protobuf is not character data; so use some kind of BLOB

As for TINY/MEDIUM/LONG; how big is your data?


TINYBLOB : max 255 bytes
BLOB : max 65,535 bytes
MEDIUMBLOB : max 16,777,215 bytes
LONGBLOB : max 4,294,967,295 bytes


In some small minority of cases TINYBLOB may suffice, especially if there aren't any strings (names/addresses in particular use up space). In most cases, MEDIUMBLOB is probably a fair guess.