正确选择 UUID 作为主键的数据类型

Question

Prior Conditions are

1. Table will have data in billions
2. Table will have secondary indexes
3. Table's primary key will be a foreign key of another table.
4. Table will have a heavy data (another column may be Text).

Primary Key must be Unique, cause my database is replicated over machine's that's why I am choosing UUID.

PS: space is also a concern so I guess Varchar(36) might be the bad idea

Answer 1

I agree with BINARY(16) . (16 bytes is better than 37.)

But UUIDs are hopelessly inefficient for huge tables. (I assume your billion-row table will not fit in RAM.)

I discuss those and more issues in http://mysql.rjweb.org/doc.php/uuid

Answer 2

I would go for BINARY(16). If you want to use CHAR then CHAR(32) is large enough without the hyphens, but BINARY is smaller and faster.