Site Restoration

#35832 ROW_FORMAT=DYNAMIC (Index column size too large. The maximum column size is 767 bytes.)

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Environment Information

PHP version
CMS Type
CMS Version
Backup Tool Version
Kickstart version

Latest post by on Tuesday, 19 October 2021 20:17 CDT


When restoring a site (table), the script fails with the error "Index column size too large. The maximum column size is 767 bytes.". The solution would be to add "ROW_FORMAT=DYNAMIC" to the SQL CREATE TABLE statement. I tried so in the sql/site.sql, but Kickstart seems to filter out that command again. Any way to achieve this?


Akeeba Staff

The ROW_FORMAT is removed from InnoDB tables since it makes it impossible to restore tables backed up on a server using the Barracuda InnoDB engine to servers using the Antelope InnoDB engine.

If you use tables with large indices you need to set innodb_file_format to Barracuda, innodb_file_per_table to ON, innodb_large_prefix to ON and innodb_default_row_format to DYNAMIC in your server's my.cnf file. Please note these are the default settings in MySQL 5.7 and 8. I don't have any older versions but you can explode the default settings in the MySQL documentation page I linked.

These settings mean that MySQL will be using the DYNAMIC row format for all InnoDB tables created. Also note that the first three options are mandatory to enable the DYNAMIC row format in MySQL with index sizes over 767 bytes. If you have all these settings already set on your MySQL server it makes no sense to use the COMPACT row format; that was the default format in Antelope because of limitations in the InnoDB engine itself, not because it's better. In fact, the DYNAMIC row format is the recommended and default InnoDB row format the past several years. It has tangible performance improvements on most tables.

Nicholas K. Dionysopoulos

Lead Developer and Director

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