Specified key was too long (부제: mysql 인덱스 생성 힘드네)

mysql에 테이블 생성하는데 에러가 발생 했다.

16:36:12 mysql_13306.sock > create table push_test     -> (col1 bigint,     -> col2 varchar(256),     -> PRIMARY KEY (col1, col2)); ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes

PK제약인가? 

다시 생성

16:36:13 mysql_13306.sock > create table push_test     -> (col1 bigint,     -> col2 varchar(256),     -> KEY push_test_idx01 (col1, col2)); ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes

여전히 안되는군.

16:45:32 mysql_13306.sock > show global variables like '%char%'; +--------------------------+-------------------------------------------------------+ | Variable_name            | Value                                                 | +--------------------------+-------------------------------------------------------+ | character_set_client     | utf8mb4                                               | | character_set_connection | utf8mb4                                               | | character_set_database   | utf8mb4                                               | | character_set_filesystem | binary                                                | | character_set_results    | utf8mb4                                               | | character_set_server     | utf8mb4                                               | | character_set_system     | utf8                                                  | | character_sets_dir       | /data1/DBSpace_mysql/MySQL_5628/13306/share/charsets/ | +--------------------------+-------------------------------------------------------+ 8 rows in set (0.00 sec)

인덱스 만들때 key 사이즈가 767바이트를 넘으면 안되는데,

utf8mb4는 1글자당 4바이트.

그럼 191글자 까지 가능.

16:51:33 mysql_13306.sock > create table push_test     -> (col1 bigint,     -> col2 varchar(256),     ->  KEY push_test_idx01 (col1, col2(192))); ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes 16:51:45 mysql_13306.sock > create table push_test     -> (col1 bigint,     -> col2 varchar(256),     ->  KEY push_test_idx01 (col1, col2(191))); Query OK, 0 rows affected (0.05 sec)

인덱스 한번 만들기 힘드네.

mysql을 사용하면 안되는 이유...