Change limit for “Mysql Row size too large”

Question

How can I change the limit

Row size too large (> 8126). 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.

Table:

id  int(11) No       
name    text    No       
date    date    No       
time    time    No       
schedule    int(11) No       
category    int(11) No       
top_a   varchar(255)    No       
top_b   varchar(255)    No       
top_c   varchar(255)    No       
top_d   varchar(255)    No       
top_e   varchar(255)    No       
top_f   varchar(255)    No       
top_g   varchar(255)    No       
top_h   varchar(255)    No       
top_i   varchar(255)    No       
top_j   varchar(255)    No       
top_title_a varchar(255)    No       
top_title_b varchar(255)    No       
top_title_c varchar(255)    No       
top_title_d varchar(255)    No       
top_title_e varchar(255)    No       
top_title_f varchar(255)    No       
top_title_g varchar(255)    No       
top_title_h varchar(255)    No       
top_title_i varchar(255)    No       
top_title_j varchar(255)    No       
top_desc_a  text    No       
top_desc_b  text    No       
top_desc_c  text    No       
top_desc_d  text    No       
top_desc_e  text    No       
top_desc_f  text    No       
top_desc_g  text    No       
top_desc_h  text    No       
top_desc_i  text    No       
top_desc_j  text    No       
status  int(11) No       
admin_id    int(11) No 

Answer 1

I ran into this issue when I was trying to restore a backed up mysql database from a different server. What solved this issue for me was adding certain settings to my.conf (like in the questions above) and additionally changing the sql backup file:

Step 1: add or edit the following lines in my.conf:

innodb_page_size=32K
innodb_file_format=Barracuda
innodb_file_per_table=1

Step 2 add ROW_FORMAT=DYNAMIC to the table create statement in the sql backup file for the table that is causing this error:

DROP TABLE IF EXISTS `problematic_table`;
/*!40101 SET @saved_cs_client = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `problematic_table` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
  ...
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 ROW_FORMAT=DYNAMIC;

the important change above is ROW_FORMAT=DYNAMIC; (that was not included in the orignal sql backup file)

source that helped me to resolve this issue: MariaDB and InnoDB MySQL Row size too large

Answer 2

After spending hours I have found the solution: just run the following SQL in your MySQL admin to convert the table to MyISAM:

USE db_name;
ALTER TABLE table_name ENGINE=MYISAM;

Answer 3

The other answers address the question asked. I will address the underlying cause: poor schema design.

Do not splay an array across columns. Here you have 3*10 columns that should be turned into 10 rows of 3 columns in a new table (plus id, etc)

Your Main table would have only

id  int(11) No       
name    text    No       
date    date    No       
time    time    No       
schedule    int(11) No       
category    int(11) No       
status  int(11) No       
admin_id    int(11) No 

Your extra table (Top) would have

id  int(11) No          -- for joining to Main
seq TINYINT UNSIGNED    -- containing 1..10
img   varchar(255)    No       
title varchar(255)    No       
desc  text    No    
PRIMARY KEY(id, seq)    -- so you can easily find the 10 top_titles

There would be 10 (or fewer? or more?) rows in Top for each id.

This eliminates your original problem, and cleans up the schema. (This is not "normalization", as debated in some of the Comments.)

Do not switch to MyISAM; it is going away.
Don't worry about ROW_FORMAT.

You will need to change your code to do the JOIN and to handle multiple rows instead of multiple columns.

Answer 4

The question has been asked on serverfault too.

You may want to take a look at this article which explains a lot about MySQL row sizes. It's important to note that even if you use TEXT or BLOB fields, your row size could still be over 8K (limit for InnoDB) because it stores the first 768 bytes for each field inline in the page.

The simplest way to fix this is to use the Barracuda file format with InnoDB. This basically gets rid of the problem altogether by only storing the 20 byte pointer to the text data instead of storing the first 768 bytes.

---

The method that worked for the OP there was:

1. Add the following to the my.cnf file under [mysqld] section.

   innodb_file_per_table=1
   innodb_file_format = Barracuda
   

2. ALTER the table to use ROW_FORMAT=COMPRESSED.

   ALTER TABLE nombre_tabla
       ENGINE=InnoDB
       ROW_FORMAT=COMPRESSED 
       KEY_BLOCK_SIZE=8;
   

---

There is a possibility that the above still does not resolve your issues. It is a known (and verified) bug with the InnoDB engine, and a temporary fix for now is to fallback to MyISAM engine as temporary storage. So, in your my.cnf file:

internal_tmp_disk_storage_engine=MyISAM