CREATE TABLE t1 (

  `c01` int(10) unsigned zerofill NOT NULL DEFAULT 0000000000,

  `c03` varchar(1024) NOT NULL DEFAULT '',

  `c04` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),

  `c06` double(16,8) DEFAULT NULL COMMENT 'Percentage',

  `c07` date DEFAULT NULL,

  `c12` varchar(64) GENERATED ALWAYS AS (concat(`c09`,' ',`c10`)) VIRTUAL,

  `c05` longblob NOT NULL DEFAULT '',

  `c11` varchar(64) GENERATED ALWAYS AS (concat(`c09`,' ',`c10`)) PERSISTENT,

  `c08` text DEFAULT '',

  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,

  `c02` char(3) NOT NULL DEFAULT '',

  `c10` bigint(20) DEFAULT NULL COMMENT 'Y',

  `c09` bigint(20) DEFAULT NULL COMMENT 'X',

  PRIMARY KEY (`id`),

  UNIQUE KEY `idx1` (`c01`,`c02`),

  KEY `idx2` (`c05`(128))

) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=COMPACT;

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

| Table   | Op    | Msg_type | Msg_text                                                                                                                                                                                            |

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

| test.t1 | check | Warning  | Row size too large (> 1982). Changing some columns to TEXT or BLOB or using ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED may help. In current row format, BLOB prefix of 768 bytes is stored inline. |

| test.t1 | check | status   | OK                                                                                                                                                                                                  |

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

MariaDB [test]> check table t1;

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

| Table   | Op    | Msg_type | Msg_text                                                                                                                                                                                            |

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

| test.t1 | check | Warning  | Row size too large (> 1982). Changing some columns to TEXT or BLOB or using ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED may help. In current row format, BLOB prefix of 768 bytes is stored inline. |

| test.t1 | check | status   | OK                                                                                                                                                                                                  |

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

2 rows in set (0.005 sec)

MariaDB [test]> check table t1;

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

| Table   | Op    | Msg_type | Msg_text |

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

| test.t1 | check | status   | OK       |

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

1 row in set (0.005 sec)

2019-07-28  0:57:51 140189814937344 [Warning] InnoDB: Cannot add field `c08` in table `test`.`t1` because after adding it, the row size is 2484 which is greater than maximum allowed size (1982) for a record on index leaf page.