mysql> show variables like '%innodb_large_prefix%';

+---------------------+-------+

| Variable_name       | Value |

+---------------------+-------+

| innodb_large_prefix | OFF   |

+---------------------+-------+

1 row in set (0.00 sec)

mysql> set global innodb_large_prefix=on;

Query OK, 0 rows affected (0.00 sec)

mysql> ALTER TABLE TEST MODIFY CODE_VALUE1 VARCHAR(350);

ERROR 1709 (HY000): Index column size too large. The maximum column size is 767 bytes.

mysql> 

mysql> show variables like '%innodb_file_format%';

+--------------------------+-----------+

| Variable_name            | Value     |

+--------------------------+-----------+

| innodb_file_format       | Antelope  |

| innodb_file_format_check | ON        |

| innodb_file_format_max   | Barracuda |

+--------------------------+-----------+

3 rows in set (0.01 sec)

mysql> set global innodb_file_format=Barracuda;

Query OK, 0 rows affected (0.00 sec)

mysql> ALTER TABLE TEST MODIFY CODE_VALUE1 VARCHAR
 
(350);

ERROR 1709 (HY000): Index column size too large. The maximum column size is 767 bytes.

mysql> 

mysql> 

mysql> show table status from MyDB where name='TEST'\G;

*************************** 1. row ***************************

           Name: TEST

         Engine: InnoDB

        Version: 10

     Row_format: Compact

           Rows: 0

 Avg_row_length: 0

    Data_length: 16384

Max_data_length: 0

   Index_length: 16384

      Data_free: 0

 Auto_increment: NULL

    Create_time: 2018-09-20 13:53:49

    Update_time: NULL

     Check_time: NULL

      Collation: utf8_general_ci

       Checksum: NULL

 Create_options: 

        Comment: 

mysql>  ALTER TABLE TEST ROW_FORMAT=DYNAMIC;

Query OK, 0 rows affected (0.05 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> show table status from MyDB where name='TEST'\G;

*************************** 1. row ***************************

           Name: TEST

         Engine: InnoDB

        Version: 10

     Row_format: Dynamic

           Rows: 0

 Avg_row_length: 0

    Data_length: 16384

Max_data_length: 0

   Index_length: 16384

      Data_free: 0

 Auto_increment: NULL

    Create_time: 2018-09-20 14:04:05

    Update_time: NULL

     Check_time: NULL

      Collation: utf8_general_ci

       Checksum: NULL

 Create_options: row_format=DYNAMIC

        Comment: 

1 row in set (0.00 sec)

ERROR: 

No query specified

mysql> ALTER TABLE TEST MODIFY CODE_VALUE1 VARCHAR(350);

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0