TINYINT vs ENUM(0, 1) for boolean values in MySQL

For the best performance and space requirements you should collect your boolean values and save them in the same TINYINT. Eg. Save up to 8 boolean values in a TINYINT. 16 boolean values in a SMALLINT etc. Both BIT(1) and ENUM uses at least 1 byte BIT(M) - approximately (M+7)/8 bytes see: https://dev.mysql.com/doc/refman/8.0/en/storage-requirements.html. So if you are storing 1 boolean value I would use TINYINT as it has the same overhead as BIT and ENUM but gives you the option to store 7 more boolean values later if you need.